Near field communication method and device in wireless power transmission system

ABSTRACT

The present invention relates to a near field communication method and device in a wireless power transmission system. A wireless power receiving device comprises: a power pick-up circuit configured to receive wireless power from a wireless power transmitting device having a primary coil by magnetic coupling to the wireless power transmitting device at an operating frequency and convert an alternating current signal generated from the wireless power into a direct current signal; a communication circuit configured to perform in-band communication with the wireless power transmitting device by using the operating frequency and perform out-band communication with the wireless power transmitting device or another device by using a frequency other than the operating frequency; and a control circuit configured to control an overall operation of the wireless power receiving device, wherein a first connection parameter for out-band communication between the wireless power transmitting device and the wireless power receiving device can be set equal to a second connection parameter for out-band communication between the wireless power transmitting device and another wireless power receiving device.

BACKGROUND OF THE DISCLOSURE Field of the Disclosure

The present disclosure relates to wireless charging, and moreparticularly, to a short-distance communication method between awireless power transmitter and a plurality of wireless power receiversin a wireless power transfer system, and an apparatus for performing thesame.

Related Art

The wireless power transfer (or transmission) technology corresponds toa technology that may wirelessly transfer (or transmit) power between apower source and an electronic device. For example, by allowing thebattery of a wireless device, such as a smartphone or a tablet PC, andso on, to be recharged by simply loading the wireless device on awireless charging pad, the wireless power transfer technique may providemore outstanding mobility, convenience, and safety as compared to theconventional wired charging environment, which uses a wired chargingconnector. Apart from the wireless charging of wireless devices, thewireless power transfer technique is raising attention as a replacementfor the conventional wired power transfer environment in diverse fields,such as electric vehicles, Bluetooth earphones, 3D glasses, diversewearable devices, household (or home) electric appliances, furniture,underground facilities, buildings, medical equipment, robots, leisure,and so on.

The wireless power transfer (or transmission) method is also referred toas a contactless power transfer method, or a no point of contact powertransfer method, or a wireless charging method. A wireless powertransfer system may be configured of a wireless power transmittersupplying electric energy by using a wireless power transfer method, anda wireless power receiver receiving the electric energy being suppliedby the wireless power transmitter and supplying the receiving electricenergy to a receiver, such as a battery cell, and so on.

The wireless power transfer technique includes diverse methods, such asa method of transferring power by using magnetic coupling, a method oftransferring power by using radio frequency (RF), a method oftransferring power by using microwaves, and a method of transferringpower by using ultrasound (or ultrasonic waves). The method that isbased on magnetic coupling is categorized as a magnetic induction methodand a magnetic resonance method. The magnetic induction methodcorresponds to a method transmitting power by using electric currentsthat are induced to the coil of the receiver by a magnetic field, whichis generated from a coil battery cell of the transmitter, in accordancewith an electromagnetic coupling between a transmitting coil and areceiving coil. The magnetic resonance method is similar to the magneticinduction method in that is uses a magnetic field. However, the magneticresonance method is different from the magnetic induction method in thatenergy is transmitted due to a concentration of magnetic fields on botha transmitting end and a receiving end, which is caused by the generatedresonance. The magnetic induction method leads the standard in thewireless power consortium (WPC), and the magnetic resonance method leadsthe standard in the air fuel alliance (AFA).

According to the WPC standard, the wireless power transmitter and thewireless power receiver are designed to exchange various statusinformation and commands related to the wireless power transmissionsystem using in-band communication. However, since in-band communicationis not a system designed specifically for communication, it is notsuitable for high-speed and large-capacity information exchange andexchange of various information. Therefore, a method for exchanginginformation related to a wireless power transmission system by combininganother wireless communication system (i.e., an out-band communicationsystem) with the existing in-band communication is being discussed. Outof band communication includes, for example, short-range communicationsuch as near field communication (NFC) and Bluetooth communication.

Short-range communication, in particular, the core spec of BluetoothSpecification V4.0 can be divided into BR/EDR (Basic Rate/Enhanced DataRate) and LE (Low Energy). Among them, BR/EDR is a wirelesscommunication technology applied to many products, occupying a dominantmarket position in short-range WPAN technology. Meanwhile, Bluetooth LowEnergy (hereinafter referred to as BLE) is a technology announced afterthe Bluetooth standard document V4.0 and was designed with the goal ofhigher energy efficiency compared to the existing Bluetooth BR/EDR.

When the wireless power receivers are placed close to the wireless powertransmitter, the wireless power transmitter negotiates for powertransmission suitable for each wireless power receiver. When thenegotiation is completed, the wireless power transmitter transmitswireless power to a plurality of wireless power receivers, the wirelesspower transmitter and the plurality of wireless power receiversperiodically exchange information necessary for wireless powertransmission using out-band communication.

When out-band communication follows the Bluetooth standard, the wirelesspower transmitter and receiver perform a role suitable for the scenarioamong the four roles defined by the Bluetooth standard: Advertiser,Scanner, Master, and Slave. Here, the scenario may include, for example,initial connection, wireless charging after connection, wirelesscharging connection of a low-power device (e.g., a mobile phone),wireless charging connection of a medium-power device (e.g., a laptop),and the like. An effective operation method according to each scenarioand role exists in the Bluetooth standard, but the existing wirelesspower transmission system is designed without considering this.

SUMMARY OF THE DISCLOSURE

An object of the present disclosure is to provide a method and apparatusfor effectively performing out-band communication in a wireless powertransmission system.

Another technical object of the present disclosure is to provide amethod and apparatus for efficiently searching for peripheral devicesand managing out-band communication in a wireless power transmissionsystem.

Another technical object of the present disclosure is to provide amethod and apparatus for preventing collision between packetstransmitted through out-band communication in a wireless powertransmission system.

According to an aspect of the present disclosure, there is provided awireless power receiver. An apparatus may comprise a power pickupcircuit configured to: receive a wireless power from a wireless powertransmitter by a magnetic coupling with the wireless power transmitterhaving a primary coil at an operating frequency, and convert an ACsignal generated by the wireless power into a DC signal, a communicationcircuit configured to: perform an in-band communication with thewireless power transmitter using the operating frequency, and perform anout-band communication with the wireless power transmitter or otherdevice using a frequency other than the operating frequency and acontrol circuit configured to control an overall operation of thewireless power receiver, wherein a first connection parameter for anout-band communication between the wireless power transmitter and thewireless power receiver may be configured a same as a second connectionparameter for an out-band communication between the wireless powertransmitter and other wireless power receiver.

In an aspect, the communication circuit may be configured to receiveinformation for the first connection parameter through the out-bandcommunication from the wireless power transmitter.

In another aspect, the communication circuit may be configured totransmit information for an interval of switching from a first mode to asecond mode to the wireless power transmitter using an out-bandcommunication.

In other aspects, the first mode and the second mode may include a modein which the wireless power receiver or the communication circuitoperates as a master and a mode in which the wireless power receiver orthe communication circuit operates as a slave.

In other aspects, the communication circuit may comprise a firstout-band communication module configured to perform the out-bandcommunication with the other device using the frequency other than theoperating frequency and a second out-band communication moduleconfigured to perform the out-band communication with the wireless powertransmitter using the frequency other than the operating frequency.

In other aspects, the first out-band communication module and the secondout-band communication module may share at least one of informationabout a scan record and scheduling information about an out-bandcommunication with each other.

In other aspects, the second out-band communication module may share thescheduling information with the first out-band communication module whena retransmission request for a packet transmitted by the wireless powerreceiver is received from the wireless power transmitter.

In other aspects, the scheduling information may include a connectioninterval and a channel map for an out-band communication.

In other aspects, the communication circuit may filter a packet based onat least one of a device identifier and a service identifier included inthe packet received through the out-band communication.

According to another aspect of the present disclosure, there is provideda wireless power transmitter supporting heterogeneous communication. Theapparatus may comprise a power conversion circuit, which has a pluralityof primary coil, configured to transmit a wireless power to a wirelesspower receiver using a primary coil that forms a magnetic coupling withthe wireless power receiver at an operating frequency and acommunication/control circuit configured to: perform an in-bandcommunication with the wireless power receiver using the operatingfrequency, and perform an out-band communication with the wireless powerreceiver using a frequency other than the operating frequency, whereinthe communication/control circuit configured to set a first connectionparameter for an out-band communication with a first wireless powerreceiver as same as a second connection parameter for an out-bandcommunication with a second wireless power receiver.

In an aspect, the communication/control circuit may be configured totransmit information for the first connection parameter to the firstwireless power receiver through the out-band communication.

In another aspect, the communication/control circuit may be configuredto: receive, from the wireless power receiver, information for aninterval at which the wireless power receiver is switched from a firstmode to a second mode, and schedule the out-band communication with thewireless power receiver based on the information for the interval.

In other aspects, the first mode and the second mode may include a modein which the wireless power receiver operates as a master and a mode inwhich the wireless power receiver operates as a slave.

In other aspects, the communication/control circuit may filter a packetbased on at least one of a device identifier and a service identifierincluded in the packet received from the wireless power receiver.

Advantageous Effects

Since the wireless power transmitter and the wireless power receiver canperform out-band communication in a mutually suitable role in thewireless power transmission system, the wireless power transmitterincluding a multi-coil can be efficiently operated.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram of a wireless power transmission system 10according to an embodiment.

FIG. 2 is a block diagram of a wireless power transmission system 10according to another embodiment.

FIG. 3a is a diagram illustrating an embodiment of various electronicdevices to which a wireless power transmission system is introduced.

FIG. 3b is a diagram illustrating an example of WPC NDEF in a wirelesspower transmission system.

FIG. 4a is a block diagram of a wireless power transmission systemaccording to another embodiment.

FIG. 4b is a diagram illustrating an example of a Bluetoothcommunication architecture to which the present disclosure can beapplied.

FIG. 4c is a block diagram illustrating a wireless power transmissionsystem using BLE communication according to an example.

FIG. 4d is a block diagram illustrating a wireless power transmissionsystem using BLE communication according to another example.

FIG. 5 is a state transition diagram for describing a wireless powertransfer procedure.

FIG. 6 is a diagram illustrating a power control method according to anembodiment.

FIG. 7 is a block diagram of a wireless power transmitter according toanother exemplary embodiment of the present disclosure.

FIG. 8 is a block diagram of an apparatus for receiving wireless poweraccording to another embodiment.

FIG. 9 is a diagram illustrating a communication frame structureaccording to an embodiment.

FIG. 10 is a structure of a sync pattern according to an exemplaryembodiment of the present disclosure.

FIG. 11 shows operation statuses of a wireless power transmitter and awireless power receiver in a shared mode according to an exemplaryembodiment of the present disclosure.

FIG. 12 is a flowchart illustrating a method of exchanging wirelesscharging-related information in an out-band or in-band by a wirelesspower transmitter and a wireless power receiver according to anembodiment.

FIG. 13 is a flowchart illustrating a method by which the wireless powerreceiver notifies the wireless power transmitter of an error accordingto an embodiment.

FIG. 14 is a diagram illustrating a situation in which a wireless powertransmitter provides a power transmission service to a plurality ofwireless power receivers.

FIG. 15 is a diagram illustrating an operation of a Bluetoothcommunication device.

FIG. 16 is a diagram for explaining terms and procedures used in thepresent embodiment.

FIG. 17 is a diagram showing the structure of roles of a wireless powertransmitter and a wireless power receiver according to an example.

FIG. 18 is a hardware block diagram of the wireless power receiveraccording to an example.

FIG. 19 is a diagram illustrating a communication link between devicesin the role structure according to FIG. 17.

FIG. 20 is a diagram showing the role structure of a wireless powertransmitter and a wireless power receiver according to another example.

FIG. 21 is a diagram illustrating a communication link between devicesin the role structure according to FIG. 20.

FIG. 22 is a flowchart illustrating a method in which a wireless powertransmitter and a wireless power receiver share a scan record andscheduling according to an embodiment.

FIG. 23 is a flowchart illustrating a method of filtering an advertisingpacket according to an embodiment.

FIG. 24 is a flowchart illustrating a communication method when thewireless power transmitter operates as a master and a scanner accordingto an embodiment.

DESCRIPTION OF EXEMPLARY EMBODIMENTS

The term “wireless power”, which will hereinafter be used in thisspecification, will be used to refer to an arbitrary form of energy thatis related to an electric field, a magnetic field, and anelectromagnetic field, which is transferred (or transmitted) from awireless power transmitter to a wireless power receiver without usingany physical electromagnetic conductors. The wireless power may also bereferred to as a wireless power signal, and this may refer to anoscillating magnetic flux that is enclosed by a primary coil and asecondary coil. For example, power conversion for wirelessly chargingdevices including mobile phones, cordless phones, iPods, MP3 players,headsets, and so on, within the system will be described in thisspecification. Generally, the basic principle of the wireless powertransfer technique includes, for example, all of a method oftransferring power by using magnetic coupling, a method of transferringpower by using radio frequency (RF), a method of transferring power byusing microwaves, and a method of transferring power by using ultrasound(or ultrasonic waves).

FIG. 1 is a block diagram of a wireless power transmission system 10according to an embodiment, and FIG. 2 is a block diagram of a wirelesspower transmission system 10 according to another embodiment.

Referring to FIG. 1, the wireless power system (10) include a wirelesspower transmitter (100) and a wireless power receiver (200).

The wireless power transmitter (100) is supplied with power from anexternal power source (S) and generates a magnetic field. The wirelesspower receiver (200) generates electric currents by using the generatedmagnetic field, thereby being capable of wirelessly receiving power.

Additionally, in the wireless power system (10), the wireless powertransmitter (100) and the wireless power receiver (200) may transceive(transmit and/or receive) diverse information that is required for thewireless power transfer. Herein, communication between the wirelesspower transmitter (100) and the wireless power receiver (200) may beperformed (or established) in accordance with any one of an in-bandcommunication, which uses a magnetic field that is used for the wirelesspower transfer (or transmission), and an out-band communication, whichuses a separate communication carrier. Out-band communication may alsobe referred to as out-of-band communication. Hereinafter, out-bandcommunication will be largely described. Examples of out-bandcommunication may include NFC, Bluetooth, Bluetooth low energy (BLE),and the like.

Herein, the wireless power transmitter (100) may be provided as a fixedtype or a mobile (or portable) type. Examples of the fixed transmittertype may include an embedded type, which is embedded in in-door ceilingsor wall surfaces or embedded in furniture, such as tables, an implantedtype, which is installed in out-door parking lots, bus stops, subwaystations, and so on, or being installed in means of transportation, suchas vehicles or trains. The mobile (or portable) type wireless powertransmitter (100) may be implemented as a part of another device, suchas a mobile device having a portable size or weight or a cover of alaptop computer, and so on.

Additionally, the wireless power receiver (200) should be interpreted asa comprehensive concept including diverse home appliances and devicesthat are operated by being wirelessly supplied with power instead ofdiverse electronic devices being equipped with a battery and a powercable. Typical examples of the wireless power receiver (200) may includeportable terminals, cellular phones, smartphones, personal digitalassistants (PDAs), portable media players (PDPs), Wibro terminals,tablet PCs, phablet, laptop computers, digital cameras, navigationterminals, television, electronic vehicles (EVs), and so on.

In the wireless power system (10), one wireless power receiver (200) ora plurality of wireless power receivers may exist. Although it is shownin FIG. 1 that the wireless power transmitter (100) and the wirelesspower receiver (200) send and receive power to and from one another in aone-to-one correspondence (or relationship), as shown in FIG. 2, it isalso possible for one wireless power transmitter (100) to simultaneouslytransfer power to multiple wireless power receivers (200-1, 200-2, . . ., 200-M). Most particularly, in case the wireless power transfer (ortransmission) is performed by using a magnetic resonance method, onewireless power transmitter (100) may transfer power to multiple wirelesspower receivers (200-1, 200-2, . . . , 200-M) by using a synchronizedtransport (or transfer) method or a time-division transport (ortransfer) method.

Additionally, although it is shown in FIG. 1 that the wireless powertransmitter (100) directly transfers (or transmits) power to thewireless power receiver (200), the wireless power system (10) may alsobe equipped with a separate wireless power transceiver, such as a relayor repeater, for increasing a wireless power transport distance betweenthe wireless power transmitter (100) and the wireless power receiver(200). In this case, power is delivered to the wireless powertransceiver from the wireless power transmitter (100), and, then, thewireless power transceiver may transfer the received power to thewireless power receiver (200).

Hereinafter, the terms wireless power receiver, power receiver, andreceiver, which are mentioned in this specification, will refer to thewireless power receiver (200). Also, the terms wireless powertransmitter, power transmitter, and transmitter, which are mentioned inthis specification, will refer to the wireless power transmitter (100).

FIG. 3a is a diagram illustrating an embodiment of various electronicdevices to which a wireless power transmission system is introduced, andFIG. 3b is a diagram illustrating an example of WPC NDEF in a wirelesspower transmission system.

As shown in FIG. 3a , the electronic devices included in the wirelesspower transfer system are sorted in accordance with the amount oftransmitted power and the amount of received power. Referring to FIG. 3,wearable devices, such as smart watches, smart glasses, head mounteddisplays (HMDs), smart rings, and so on, and mobile electronic devices(or portable electronic devices), such as earphones, remote controllers,smartphones, PDAs, tablet PCs, and so on, may adopt a low-power(approximately 5W or less or approximately 20W or less) wirelesscharging method.

Small-sized/Mid-sized electronic devices, such as laptop computers,robot vacuum cleaners, TV receivers, audio devices, vacuum cleaners,monitors, and so on, may adopt a mid-power (approximately 50W or less orapproximately 200W or less) wireless charging method. Kitchenappliances, such as mixers, microwave ovens, electric rice cookers, andso on, and personal transportation devices (or other electric devices ormeans of transportation), such as powered wheelchairs, powered kickscooters, powered bicycles, electric cars, and so on may adopt ahigh-power (approximately 2 kW or less or approximately 22 kW or less)wireless charging method.

The electric devices or means of transportation, which are describedabove (or shown in FIG. 1) may each include a wireless power receiver,which will hereinafter be described in detail. Therefore, theabove-described electric devices or means of transportation may becharged (or re-charged) by wirelessly receiving power from a wirelesspower transmitter.

Hereinafter, although the present disclosure will be described based ona mobile device adopting the wireless power charging method, this ismerely exemplary. And, therefore, it shall be understood that thewireless charging method according to the present disclosure may beapplied to diverse electronic devices.

A standard for the wireless power transfer (or transmission) includes awireless power consortium (WPC), an air fuel alliance (AFA), and a powermatters alliance (PMA).

The WPC standard defines a baseline power profile (BPP) and an extendedpower profile (EPP). The BPP is related to a wireless power transmitterand a wireless power receiver supporting a power transfer of 5W, and theEPP is related to a wireless power transmitter and a wireless powerreceiver supporting the transfer of a power range greater than 5W andless than 30W.

Diverse wireless power transmitters and wireless power receivers eachusing a different power level may be covered by each standard and may besorted by different power classes or categories.

For example, the WPC may categorize (or sort) the wireless powertransmitters and the wireless power receivers as PC-1, PC0, PC1, andPC2, and the WPC may provide a standard document (or specification) foreach power class (PC). The PC-1 standard relates to wireless powertransmitters and receivers providing a guaranteed power of less than 5W.The application of PC-1 includes wearable devices, such as smartwatches.

The PC0 standard relates to wireless power transmitters and receiversproviding a guaranteed power of 5W. The PC0 standard includes an EPPhaving a guaranteed power ranges that extends to 30W. Although in-band(IB) communication corresponds to a mandatory communication protocol ofPC0, out-of-band (OOB) communication that is used as an optional backupchannel may also be used for PC0. The wireless power receiver may beidentified by setting up an OOB flag, which indicates whether or not theOOB is supported, within a configuration packet. A wireless powertransmitter supporting the OOB may enter an OOB handover phase bytransmitting a bit-pattern for an OOB handover as a response to theconfiguration packet. The response to the configuration packet maycorrespond to an NAK, an ND, or an 8-bit pattern that is newly defined.The application of the PC0 includes smartphones.

The PC1 standard relates to wireless power transmitters and receiversproviding a guaranteed power ranging from 30W to 150W. OOB correspondsto a mandatory communication channel for PC1, and IB is used forinitialization and link establishment to OOB. The wireless powertransmitter may enter an OOB handover phase by transmitting abit-pattern for an OOB handover as a response to the configurationpacket. The application of the PC1 includes laptop computers or powertools.

The PC2 standard relates to wireless power transmitters and receiversproviding a guaranteed power ranging from 200W to 2 kW, and itsapplication includes kitchen appliances.

As described above, the PCs may be differentiated in accordance with therespective power levels. And, information on whether or not thecompatibility between the same PCs is supported may be optional ormandatory. Herein, the compatibility between the same PCs indicates thatpower transfer/reception between the same PCs is possible. For example,in case a wireless power transmitter corresponding to PC x is capable ofperforming charging of a wireless power receiver having the same PC x,it may be understood that compatibility is maintained between the samePCs. Similarly, compatibility between different PCs may also besupported. Herein, the compatibility between different PCs indicatesthat power transfer/reception between different PCs is also possible.For example, in case a wireless power transmitter corresponding to PC xis capable of performing charging of a wireless power receiver having PCy, it may be understood that compatibility is maintained between thedifferent PCs.

The support of compatibility between PCs corresponds to an extremelyimportant issue in the aspect of user experience and establishment ofinfrastructure. Herein, however, diverse problems, which will bedescribed below, exist in maintaining the compatibility between PCs.

In case of the compatibility between the same PCs, for example, in caseof a wireless power receiver using a lap-top charging method, whereinstable charging is possible only when power is continuously transferred,even if its respective wireless power transmitter has the same PC, itmay be difficult for the corresponding wireless power receiver to stablyreceive power from a wireless power transmitter of the power toolmethod, which transfers power non-continuously. Additionally, in case ofthe compatibility between different PCs, for example, in case a wirelesspower transmitter having a minimum guaranteed power of 200W transferspower to a wireless power receiver having a maximum guaranteed power of5W, the corresponding wireless power receiver may be damaged due to anovervoltage. As a result, it may be inappropriate (or difficult) to usethe PS as an index/reference standard representing/indicating thecompatibility.

Wireless power transmitters and receivers may provide a very convenientuser experience and interface (UX/UI). That is, a smart wirelesscharging service may be provided, and the smart wireless chargingservice may be implemented based on a UX/UI of a smartphone including awireless power transmitter. For these applications, an interface betweena processor of a smartphone and a wireless charging receiver allows for“drop and play” two-way communication between the wireless powertransmitter and the wireless power receiver.

As an example, a user may experience a smart wireless charging servicein a hotel. When the user enters a hotel room and puts a smartphone on awireless charger in the room, the wireless charger transmits wirelesspower to the smartphone and the smartphone receives wireless power. Inthis process, the wireless charger transmits information on the smartwireless charging service to the smartphone. When it is detected thatthe smartphone is located on the wireless charger, when it is detectedthat wireless power is received, or when the smartphone receivesinformation on the smart wireless charging service from the wirelesscharger, the smartphone enters a state of inquiring the user aboutagreement (opt-in) of supplemental features. To this end, the smartphonemay display a message on a screen in a manner with or without an alarmsound. An example of the message may include the phrase “Welcome to ###hotel. Select” Yes” to activate smart charging functions: Yes|NoThanks.” The smartphone receives an input from the user who selects Yesor No Thanks, and performs a next procedure selected by the user. If Yesis selected, the smartphone transmits corresponding information to thewireless charger. The smartphone and the wireless charger perform thesmart charging function together.

The smart wireless charging service may also include receiving WiFicredentials auto-filled. For example, the wireless charger transmits theWiFi credentials to the smartphone, and the smartphone automaticallyinputs the WiFi credentials received from the wireless charger byrunning an appropriate application.

The smart wireless charging service may also include running a hotelapplication that provides hotel promotions or obtaining remotecheck-in/check-out and contact information.

As another example, the user may experience the smart wireless chargingservice in a vehicle. When the user gets in the vehicle and puts thesmartphone on the wireless charger, the wireless charger transmitswireless power to the smartphone and the smartphone receives wirelesspower. In this process, the wireless charger transmits information onthe smart wireless charging service to the smartphone. When it isdetected that the smartphone is located on the wireless charger, whenwireless power is detected to be received, or when the smartphonereceives information on the smart wireless charging service from thewireless charger, the smartphone enters a state of inquiring the userabout checking identity.

In this state, the smartphone is automatically connected to the vehiclevia WiFi and/or Bluetooth. The smartphone may display a message on thescreen in a manner with or without an alarm sound. An example of themessage may include a phrase of “Welcome to your car. Select “Yes” tosynch device with in-car controls: Yes No Thanks.” Upon receiving theuser's input to select Yes or No Thanks, the smartphone performs a nextprocedure selected by the user. If Yes is selected, the smartphonetransmits corresponding information to the wireless charger. Inaddition, the smartphone and the wireless charger may run an in-vehiclesmart control function together by driving in-vehicleapplication/display software. The user may enjoy the desired music andcheck a regular map location. The in-vehicle applications/displaysoftware may include an ability to provide synchronous access forpassers-by.

As another example, the user may experience smart wireless charging athome. When the user enters the room and puts the smartphone on thewireless charger in the room, the wireless charger transmits wirelesspower to the smartphone and the smartphone receives wireless power. Inthis process, the wireless charger transmits information on the smartwireless charging service to the smartphone. When it is detected thatthe smartphone is located on the wireless charger, when wireless poweris detected to be received, or when the smartphone receives informationon the smart wireless charging service from the wireless charger, thesmartphone enters a state of inquiring the user about agreement (opt-in)of supplemental features. To this end, the smartphone may display amessage on the screen in a manner with or without an alarm sound. Anexample of the message may include a phrase such as “Hi xxx, Would youlike to activate night mode and secure the building?: Yes|No Thanks.”The smartphone receives a user input to select Yes or No Thanks andperforms a next procedure selected by the user. If Yes is selected, thesmartphone transmits corresponding information to the wireless charger.The smartphones and the wireless charger may recognize at least user'spattern and recommend the user to lock doors and windows, turn offlights, or set an alarm.

Hereinafter, ‘profiles’ will be newly defined based on indexes/referencestandards representing/indicating the compatibility. More specifically,it may be understood that by maintaining compatibility between wirelesspower transmitters and receivers having the same ‘profile’, stable powertransfer/reception may be performed, and that power transfer/receptionbetween wireless power transmitters and receivers having different‘profiles’ cannot be performed. The ‘profiles’ may be defined inaccordance with whether or not compatibility is possible and/or theapplication regardless of (or independent from) the power class.

For example, the profile may be sorted into 4 different categories, suchas i) Mobile, ii) Power tool, iii) Kitchen, and iv) Wearable.

In case of the ‘Mobile’ profile, the PC may be defined as PC0 and/orPC1, the communication protocol/method may be defined as IB and OOBcommunication, and the operation frequency may be defined as 87 to 205kHz, and smartphones, laptop computers, and so on, may exist as theexemplary application.

In case of the ‘Power tool’ profile, the PC may be defined as PC1, thecommunication protocol/method may be defined as IB communication, andthe operation frequency may be defined as 87 to 145 kHz, and powertools, and so on, may exist as the exemplary application.

In case of the ‘Kitchen’ profile, the PC may be defined as PC2, thecommunication protocol/method may be defined as NFC-based communication,and the operation frequency may be defined as less than 100 kHz, andkitchen/home appliances, and so on, may exist as the exemplaryapplication.

In the case of power tools and kitchen profiles, NFC communication maybe used between the wireless power transmitter and the wireless powerreceiver. The wireless power transmitter and the wireless power receivermay confirm that they are NFC devices with each other by exchanging WPCNFC data exchange profile format (NDEF). For example, referring to FIG.3b , the WPC NDEF may include, for example, an application profile field(e.g., 1B), a version field (e.g., 1B), and profile specific data (e.g.,1B). The application profile field indicates whether the correspondingdevice is i) mobile and computing, ii) power tool, and iii) kitchen, andan upper nibble in the version field indicates a major version and alower nibble indicates a minor version. In addition, profile-specificdata defines content for the kitchen.

In case of the ‘Wearable’ profile, the PC may be defined as PC-1, thecommunication protocol/method may be defined as IB communication, andthe operation frequency may be defined as 87 to 205 kHz, and wearabledevices that are worn by the users, and so on, may exist as theexemplary application.

It may be mandatory to maintain compatibility between the same profiles,and it may be optional to maintain compatibility between differentprofiles.

The above-described profiles (Mobile profile, Power tool profile,Kitchen profile, and Wearable profile) may be generalized and expressedas first to nth profile, and a new profile may be added/replaced inaccordance with the WPC standard and the exemplary embodiment.

In case the profile is defined as described above, the wireless powertransmitter may optionally perform power transfer only to the wirelesspower receiving corresponding to the same profile as the wireless powertransmitter, thereby being capable of performing a more stable powertransfer. Additionally, since the load (or burden) of the wireless powertransmitter may be reduced and power transfer is not attempted to awireless power receiver for which compatibility is not possible, therisk of damage in the wireless power receiver may be reduced.

PC1 of the ‘Mobile’ profile may be defined by being derived from anoptional extension, such as OOB, based on PC0. And, the ‘Power tool’profile may be defined as a simply modified version of the PC1 ‘Mobile’profile. Additionally, up until now, although the profiles have beendefined for the purpose of maintaining compatibility between the sameprofiles, in the future, the technology may be evolved to a level ofmaintaining compatibility between different profiles. The wireless powertransmitter or the wireless power receiver may notify (or announce) itsprofile to its counterpart by using diverse methods.

In the AFA standard, the wireless power transmitter is referred to as apower transmitting unit (PTU), and the wireless power receiver isreferred to as a power receiving unit (PRU). And, the PTU is categorizedto multiple classes, as shown in Table 1, and the PRU is categorized tomultiple classes, as shown in Table 2.

TABLE 1 Minimum value for a Minimum category maximum number of PTUP_(TX) _(—) _(IN) _(—) _(MAX) support requirement supported devicesClass 1  2 W 1x Category 1 1x Category 1 Class 2 10 W 1x Category 3 2xCategory 2 Class 3 16 W 1x Category 4 2x Category 3 Class 4 33 W 1xCategory 5 3x Category 3 Class 5 50 W 1x Category 6 4x Category 3 Class6 70 W 1x Category 7 5x Category 3

TABLE 2 PRU P_(RX) _(—) _(OUT) _(—) _(MAX′) Exemplary applicationCategory 1 TBD Bluetooth headset Category 2 3.5 W  Feature phoneCategory 3 6.5 W  Smartphone Category 4 13 W Tablet PC, Phablet Category5 25 W Small form factor laptop Category 6 37.5 W  General laptopCategory 7 50 W Home appliance

As shown in Table 1, a maximum output power capability of Class n PTUmay be equal to or greater than the PTX_IN_MAX of the correspondingclass. The PRU cannot draw a power that is higher than the power levelspecified in the corresponding category.

FIG. 4a is a block diagram of a wireless power transmission systemaccording to another embodiment, and FIG. 4b is a diagram illustratingan example of a Bluetooth communication architecture to which thepresent disclosure can be applied.

Referring to FIG. 4a , the wireless power transfer system (10) includesa mobile device (450), which wirelessly receives power, and a basestation (400), which wirelessly transmits power.

As a device providing induction power or resonance power, the basestation (400) may include at least one of a wireless power transmitter(100) and a system unit (405). The wireless power transmitter (100) maytransmit induction power or resonance power and may control thetransmission. The wireless power transmitter (100) may include a powerconversion unit (110) converting electric energy to a power signal bygenerating a magnetic field through a primary coil (or primary coils),and a communications & control unit (120) controlling the communicationand power transfer between the wireless power receiver (200) in order totransfer power at an appropriate (or suitable) level. The system unit(405) may perform input power provisioning, controlling of multiplewireless power transmitters, and other operation controls of the basestation (400), such as user interface control.

The primary coil may generate an electromagnetic field by using analternating current power (or voltage or current). The primary coil issupplied with an alternating current power (or voltage or current) of aspecific frequency, which is being outputted from the power conversionunit (110). And, accordingly, the primary coil may generate a magneticfield of the specific frequency. The magnetic field may be generated ina non-radial shape or a radial shape. And, the wireless power receiver(200) receives the generated magnetic field and then generates anelectric current. In other words, the primary coil wirelessly transmitspower.

In the magnetic induction method, a primary coil and a secondary coilmay have randomly appropriate shapes. For example, the primary coil andthe secondary coil may correspond to copper wire being wound around ahigh-permeability formation, such as ferrite or a non-crystalline metal.The primary coil may also be referred to as a primary core, a primarywinding, a primary loop antenna, and so on. Meanwhile, the secondarycoil may also be referred to as a secondary core, a secondary winding, asecondary loop antenna, a pickup antenna, and so on.

In case of using the magnetic resonance method, the primary coil and thesecondary coil may each be provided in the form of a primary resonanceantenna and a secondary resonance antenna. The resonance antenna mayhave a resonance structure including a coil and a capacitor. At thispoint, the resonance frequency of the resonance antenna may bedetermined by the inductance of the coil and a capacitance of thecapacitor. Herein, the coil may be formed to have a loop shape. And, acore may be placed inside the loop. The core may include a physicalcore, such as a ferrite core, or an air core.

The energy transmission (or transfer) between the primary resonanceantenna and the second resonance antenna may be performed by a resonancephenomenon occurring in the magnetic field. When a near fieldcorresponding to a resonance frequency occurs in a resonance antenna,and in case another resonance antenna exists near the correspondingresonance antenna, the resonance phenomenon refers to a highly efficientenergy transfer occurring between the two resonance antennas that arecoupled with one another. When a magnetic field corresponding to theresonance frequency is generated between the primary resonance antennaand the secondary resonance antenna, the primary resonance antenna andthe secondary resonance antenna resonate with one another. And,accordingly, in a general case, the magnetic field is focused toward thesecond resonance antenna at a higher efficiency as compared to a casewhere the magnetic field that is generated from the primary antenna isradiated to a free space. And, therefore, energy may be transferred tothe second resonance antenna from the first resonance antenna at a highefficiency. The magnetic induction method may be implemented similarlyto the magnetic resonance method. However, in this case, the frequencyof the magnetic field is not required to be a resonance frequency.Nevertheless, in the magnetic induction method, the loops configuringthe primary coil and the secondary coil are required to match oneanother, and the distance between the loops should be very close-ranged.

Although it is not shown in the drawing, the wireless power transmitter(100) may further include a communication antenna. The communicationantenna may transmit and/or receive a communication signal by using acommunication carrier apart from the magnetic field communication. Forexample, the communication antenna may transmit and/or receivecommunication signals corresponding to Wi-Fi, Bluetooth, Bluetooth LE,ZigBee, NFC, and so on.

The communications & control unit (120) may transmit and/or receiveinformation to and from the wireless power receiver (200). Thecommunications & control unit (120) may include at least one of an IBcommunication module and an OOB communication module.

The IB communication module may transmit and receive information using amagnetic wave having a specific frequency as a center frequency. Forexample, the communication/control circuit 120 may perform in-bandcommunication by loading information on a magnetic wave and transmittingit through a primary coil or by receiving a magnetic wave containinginformation through a primary coil. At this time, using a modulationmethod such as binary phase shift keying (BPSK) or amplitude shiftkeying (ASK) and a coding method such as Manchester coding ornon-return-to-zero level (NZR-L) coding, it can contain information inmagnetic waves or interpret magnetic waves containing information. Ifsuch D3 communication is used, the communication/control circuit 120 maytransmit/receive information up to a distance of several meters at adata rate of several kbps.

The OOB communication module may also perform out-of-band communicationthrough a communication antenna. For example, the communications &control unit (120) may be provided to a near field communication module.Examples of the near field communication module may includecommunication modules, such as Wi-Fi, Bluetooth, Bluetooth LE, ZigBee,NFC, and so on.

The communications & control unit (120) may control the overalloperations of the wireless power transmitter (100). The communications &control unit (120) may perform calculation and processing of diverseinformation and may also control each configuration element of thewireless power transmitter (100).

The communications & control unit (120) may be implemented in a computeror a similar device as hardware, software, or a combination of the same.When implemented in the form of hardware, the communications & controlunit (120) may be provided as an electronic circuit performing controlfunctions by processing electrical signals. And, when implemented in theform of software, the communications & control unit (120) may beprovided as a program that operates the communications & control unit(120).

By controlling the operating point, the communications & control unit(120) may control the transmitted power. The operating point that isbeing controlled may correspond to a combination of a frequency (orphase), a duty cycle, a duty ratio, and a voltage amplitude. Thecommunications & control unit (120) may control the transmitted power byadjusting any one of the frequency (or phase), the duty cycle, the dutyratio, and the voltage amplitude. Additionally, the wireless powertransmitter (100) may supply a consistent level of power, and thewireless power receiver (200) may control the level of received power bycontrolling the resonance frequency.

The mobile device (450) includes a wireless power receiver (200)receiving wireless power through a secondary coil, and a load (455)receiving and storing the power that is received by the wireless powerreceiver (200) and supplying the received power to the device.

The wireless power receiver (200) may include a power pick-up unit (210)and a communications & control unit (220). The power pick-up unit (210)may receive wireless power through the secondary coil and may convertthe received wireless power to electric energy. The power pick-up unit(210) rectifies the alternating current (AC) signal, which is receivedthrough the secondary coil, and converts the rectified signal to adirect current (DC) signal. The communications & control unit (220) maycontrol the transmission and reception of the wireless power (transferand reception of power).

The secondary coil may receive wireless power that is being transmittedfrom the wireless power transmitter (100). The secondary coil mayreceive power by using the magnetic field that is generated in theprimary coil. Herein, in case the specific frequency corresponds aresonance frequency, magnetic resonance may occur between the primarycoil and the secondary coil, thereby allowing power to be transferredwith greater efficiency.

Although it is not shown in FIG. 4a , the communications & control unit(220) may further include a communication antenna. The communicationantenna may transmit and/or receive a communication signal by using acommunication carrier apart from the magnetic field communication. Forexample, the communication antenna may transmit and/or receivecommunication signals corresponding to Wi-Fi, Bluetooth, Bluetooth LE,ZigBee, NFC, and so on.

The communications & control unit (220) may transmit and/or receiveinformation to and from the wireless power transmitter (100). Thecommunications & control unit (220) may include at least one of an IBcommunication module and an OOB communication module.

The IB communication module may transmit and receive information using amagnetic wave having a specific frequency as a center frequency. Forexample, the communication/control circuit 220 may perform in-bandcommunication by loading information on a magnetic wave and transmittingit through a primary coil or by receiving a magnetic wave containinginformation through a primary coil. At this time, using a modulationmethod such as binary phase shift keying (BPSK) or amplitude shiftkeying (ASK) and a coding method such as Manchester coding ornon-return-to-zero level (NZR-L) coding, it can contain information inmagnetic waves or interpret magnetic waves containing information. Ifsuch D3 communication is used, the communication/control circuit 220 maytransmit/receive information up to a distance of several meters at adata rate of several kbps.

The OOB communication module may also perform out-of-band communicationthrough a communication antenna. For example, the communications &control unit (220) may be provided to a near field communication module.

Examples of the near field communication module may includecommunication modules, such as Wi-Fi, Bluetooth, Bluetooth LE, ZigBee,NFC, and so on.

The communications & control unit (220) may control the overalloperations of the wireless power receiver (200). The communications &control unit (220) may perform calculation and processing of diverseinformation and may also control each configuration element of thewireless power receiver (200).

The communications & control unit (220) may be implemented in a computeror a similar device as hardware, software, or a combination of the same.When implemented in the form of hardware, the communications & controlunit (220) may be provided as an electronic circuit performing controlfunctions by processing electrical signals. And, when implemented in theform of software, the communications & control unit (220) may beprovided as a program that operates the communications & control unit(220).

When the communication/control circuit 120 and the communication/controlcircuit 220 are Bluetooth or Bluetooth LE as an OOB communication moduleor a short-range communication module, the communication/control circuit120 and the communication/control circuit 220 may each be implementedand operated with a communication architecture as shown in FIG. 4 b.

Referring to FIG. 4b , an example of a protocol stack of Bluetooth BR(Basic Rate)/EDR (Enhanced Data Rate) and Bluetooth LE (Low Energy)supporting GATT is illustrated.

Specifically, the Bluetooth BR/EDR protocol stack may include an uppercontrol stack 460 and a lower host stack 470 based on a host controllerinterface (HCI) 18.

The host stack (or host module) 470 refers to hardware for transmittingor receiving a Bluetooth packet to or from a wirelesstransmission/reception module which receives a Bluetooth signal of 2.4GHz, and the controller stack 460 is connected to the Bluetooth moduleto control the Bluetooth module and perform an operation.

The host stack 470 may include a BR/EDR PHY layer 12, a BR/EDR basebandlayer 14, and a link manager layer 16.

The BR/EDR PHY layer 12 is a layer that transmits and receives a 2.4 GHzradio signal, and in the case of using Gaussian frequency shift keying(GFSK) modulation, the BR/EDR PHY layer 12 may transmit data by hopping79 RF channels.

The BR/EDR baseband layer 14 serves to transmit a digital signal,selects a channel sequence for hopping 1400 times per second, andtransmits a time slot with a length of 625 us for each channel.

The link manager layer 16 controls an overall operation (link setup,control, security) of Bluetooth connection by utilizing a link managerprotocol (LMP).

The link manager layer 16 may perform the following functions.

-   -   Performs ACL/SCO logical transport, logical link setup, and        control.    -   Detach: It interrupts connection and informs a counterpart        device about a reason for the interruption.    -   Performs power control and role switch.    -   Performs security (authentication, pairing, encryption)        function.

The host controller interface layer 18 provides an interface between ahost module and a controller module so that a host provides commands anddata to the controller and the controller provides events and data tothe host.

The host stack (or host module, 470) includes a logical link control andadaptation protocol (L2CAP) 21, an attribute protocol 22, a genericattribute profile (GATT) 23, a generic access profile (GAP) 24, and aBR/EDR profile 25.

The logical link control and adaptation protocol (L2CAP) 21 may provideone bidirectional channel for transmitting data to a specific protocolor profile.

The L2CAP 21 may multiplex various protocols, profiles, etc., providedfrom upper Bluetooth.

L2CAP of Bluetooth BR/EDR uses dynamic channels, supports protocolservice multiplexer, retransmission, streaming mode, and providessegmentation and reassembly, per-channel flow control, and errorcontrol.

The generic attribute profile (GATT) 23 may be operable as a protocolthat describes how the attribute protocol 22 is used when services areconfigured. For example, the generic attribute profile 23 may beoperable to specify how ATT attributes are grouped together intoservices and may be operable to describe features associated withservices.

Accordingly, the generic attribute profile 23 and the attributeprotocols (ATT) 22 may use features to describe device's state andservices, how features are related to each other, and how they are used.

The attribute protocol 22 and the BR/EDR profile 25 define a service(profile) using Bluetooth BR/EDR and an application protocol forexchanging these data, and the generic access profile (GAP) 24 definesdevice discovery, connectivity, and security level.

Next, the Bluetooth LE protocol stack includes a controller stack 480operable to process a wireless device interface important in timing anda host stack 490 operable to process high level data.

First, the controller stack 480 may be implemented using a communicationmodule that may include a Bluetooth wireless device, for example, aprocessor module that may include a processing device such as amicroprocessor.

The host stack 490 may be implemented as a part of an OS running on aprocessor module or as an instantiation of a package on the OS.

In some cases, the controller stack and the host stack may be run orexecuted on the same processing device in a processor module.

The controller stack 480 includes a physical layer (PHY) 32, a linklayer 34, and a host controller interface 36.

The physical layer (PHY, wireless transmission/reception module) 32 is alayer that transmits and receives a 2.4 GHz radio signal and usesGaussian frequency shift keying (GFSK) modulation and a frequencyhopping scheme including 40 RF channels.

The link layer 34, which serves to transmit or receive Bluetoothpackets, creates connections between devices after performingadvertising and scanning functions using 3 advertising channels andprovides a function of exchanging data packets of up to 257 bytesthrough 37 data channels.

The host stack includes a generic access profile (GAP) 45, a logicallink control and adaptation protocol (L2CAP, 41), a security manager(SM) 42, and an attribute protocol (ATT) 43, a generic attribute profile(GATT) 44, a generic access profile 45, and an LE profile 46. However,the host stack 490 is not limited thereto and may include variousprotocols and profiles.

The host stack multiplexes various protocols, profiles, etc., providedfrom upper Bluetooth using L2CAP.

First, the logical link control and adaptation protocol (L2CAP) 41 mayprovide one bidirectional channel for transmitting data to a specificprotocol or profile.

The L2CAP 41 may be operable to multiplex data between higher layerprotocols, segment and reassemble packages, and manage multicast datatransmission.

In Bluetooth LE, three fixed channels (one for signaling CH, one forsecurity manager, and one for attribute protocol) are basically used.Also, a dynamic channel may be used as needed.

Meanwhile, a basic channel/enhanced data rate (BR/EDR) uses a dynamicchannel and supports protocol service multiplexer, retransmission,streaming mode, and the like.

The security manager (SM) 42 is a protocol for authenticating devicesand providing key distribution.

The attribute protocol (ATT) 43 defines a rule for accessing data of acounterpart device in a server-client structure. The ATT has thefollowing 6 message types (request, response, command, notification,indication, confirmation).

{circle around (1)} Request and Response message: A request message is amessage for requesting specific information from the client device tothe server device, and the response message is a response message to therequest message, which is a message transmitted from the server deviceto the client device.

{circle around (2)} Command message: It is a message transmitted fromthe client device to the server device in order to indicate a command ofa specific operation. The server device does not transmit a responsewith respect to the command message to the client device.

{circle around (3)} Notification message: It is a message transmittedfrom the server device to the client device in order to notify an event,or the like. The client device does not transmit a confirmation messagewith respect to the notification message to the server device.

{circle around (4)} Indication and confirmation message: It is a messagetransmitted from the server device to the client device in order tonotify an event, or the like. Unlike the notification message, theclient device transmits a confirmation message regarding the indicationmessage to the server device.

In the present disclosure, when the GATT profile using the attributeprotocol (ATT) 43 requests long data, a value regarding a data length istransmitted to allow a client to clearly know the data length, and acharacteristic value may be received from a server by using a universalunique identifier (UUID).

The generic access profile (GAP) 45, a layer newly implemented for theBluetooth LE technology, is used to select a role for communicationbetween Bluetooth LED devices and to control how a multi-profileoperation takes place.

Also, the generic access profile (GAP) 45 is mainly used for devicediscovery, connection generation, and security procedure part, defines ascheme for providing information to a user, and defines types ofattributes as follows.

{circle around (1)} Service: It defines a basic operation of a device bya combination of behaviors related to data

{circle around (2)} Include: It defines a relationship between services

{circle around (3)} Characteristics: It is a data value used in a server

{circle around (4)} Behavior: It is a format that may be read by acomputer defined by a UUID (value type).

The LE profile 46, including profiles dependent upon the GATT, is mainlyapplied to a Bluetooth LE device. The LE profile 46 may include, forexample, Battery, Time, FindMe, Proximity, Time, Object DeliveryService, and the like, and details of the GATT-based profiles are asfollows.

{circle around (1)} Battery: Battery information exchanging method

{circle around (2)} Time: Time information exchanging method

{circle around (3)} FindMe: Provision of alarm service according todistance

{circle around (4)} Proximity: Battery information exchanging method

The generic attribute profile (GATT) 44 may operate as a protocoldescribing how the attribute protocol (ATT) 43 is used when services areconfigured. For example, the GATT 44 may operate to define how ATTattributes are grouped together with services and operate to describefeatures associated with services.

Thus, the GATT 44 and the ATT 43 may use features in order to describestatus and services of a device and describe how the features arerelated and used.

Hereinafter, procedures of the Bluetooth low energy (BLE) technologywill be briefly described.

The BLE procedure may be classified as a device filtering procedure, anadvertising procedure, a scanning procedure, a discovering procedure,and a connecting procedure.

Device Filtering Procedure

The device filtering procedure is a method for reducing the number ofdevices performing a response with respect to a request, indication,notification, and the like, in the controller stack.

When requests are received from all the devices, it is not necessary torespond thereto, and thus, the controller stack may perform control toreduce the number of transmitted requests to reduce power consumption.

An advertising device or scanning device may perform the devicefiltering procedure to limit devices for receiving an advertisingpacket, a scan request or a connection request.

Here, the advertising device refers to a device transmitting anadvertising event, that is, a device performing an advertisement and isalso termed an advertiser.

The scanning device refers to a device performing scanning, that is, adevice transmitting a scan request.

In the BLE, in a case in which the scanning device receives someadvertising packets from the advertising device, the scanning deviceshould transmit a scan request to the advertising device.

However, in a case in which a device filtering procedure is used so ascan request transmission is not required, the scanning device maydisregard the advertising packets transmitted from the advertisingdevice.

Even in a connection request process, the device filtering procedure maybe used. In a case in which device filtering is used in the connectionrequest process, it is not necessary to transmit a response with respectto the connection request by disregarding the connection request.

Advertising Procedure

The advertising device performs an advertising procedure to performundirected broadcast to devices within a region.

Here, the undirected broadcast is advertising toward all the devices,rather than broadcast toward a specific device, and all the devices mayscan advertising to make an supplemental information request or aconnection request.

In contrast, directed advertising may make an supplemental informationrequest or a connection request by scanning advertising for only adevice designated as a reception device.

The advertising procedure is used to establish a Bluetooth connectionwith an initiating device nearby.

Or, the advertising procedure may be used to provide periodicalbroadcast of user data to scanning devices performing listening in anadvertising channel.

In the advertising procedure, all the advertisements (or advertisingevents) are broadcast through an advertisement physical channel.

The advertising devices may receive scan requests from listening devicesperforming listening to obtain additional user data from advertisingdevices. The advertising devices transmit responses with respect to thescan requests to the devices which have transmitted the scan requests,through the same advertising physical channels as the advertisingphysical channels in which the scan requests have been received.

Broadcast user data sent as part of advertising packets are dynamicdata, while the scan response data is generally static data.

The advertisement device may receive a connection request from aninitiating device on an advertising (broadcast) physical channel. If theadvertising device has used a connectable advertising event and theinitiating device has not been filtered according to the devicefiltering procedure, the advertising device may stop advertising andenter a connected mode. The advertising device may start advertisingafter the connected mode.

Scanning Procedure

A device performing scanning, that is, a scanning device performs ascanning procedure to listen to undirected broadcasting of user datafrom advertising devices using an advertising physical channel.

The scanning device transmits a scan request to an advertising devicethrough an advertising physical channel in order to request additionaldata from the advertising device. The advertising device transmits ascan response as a response with respect to the scan request, byincluding additional user data which has requested by the scanningdevice through an advertising physical channel.

The scanning procedure may be used while being connected to other BLEdevice in the BLE piconet.

If the scanning device is in an initiator mode in which the scanningdevice may receive an advertising event and initiates a connectionrequest. The scanning device may transmit a connection request to theadvertising device through the advertising physical channel to start aBluetooth connection with the advertising device.

When the scanning device transmits a connection request to theadvertising device, the scanning device stops the initiator modescanning for additional broadcast and enters the connected mode.

Discovering Procedure

Devices available for Bluetooth communication (hereinafter, referred toas “Bluetooth devices”) perform an advertising procedure and a scanningprocedure in order to discover devices located nearby or in order to bediscovered by other devices within a given area.

The discovering procedure is performed asymmetrically. A Bluetoothdevice intending to discover other device nearby is termed a discoveringdevice, and listens to discover devices advertising an advertising eventthat may be scanned. A Bluetooth device which may be discovered by otherdevice and available to be used is termed a discoverable device andpositively broadcasts an advertising event such that it may be scannedby other device through an advertising (broadcast) physical channel.

Both the discovering device and the discoverable device may have alreadybeen connected with other Bluetooth devices in a piconet.

Connecting Procedure

A connecting procedure is asymmetrical, and requests that, while aspecific Bluetooth device is performing an advertising procedure,another Bluetooth device should perform a scanning procedure.

That is, an advertising procedure may be aimed, and as a result, onlyone device may response to the advertising. After a connectableadvertising event is received from an advertising device, a connectingrequest may be transmitted to the advertising device through anadvertising (broadcast) physical channel to initiate connection.

Hereinafter, operational states, that is, an advertising state, ascanning state, an initiating state, and a connection state, in the BLEtechnology will be briefly described.

Advertising State

A link layer (LL) enters an advertising state according to aninstruction from a host (stack). In a case in which the LL is in theadvertising state, the LL transmits an advertising packet data unit(PDU) in advertising events.

Each of the advertising events include at least one advertising PDU, andthe advertising PDU is transmitted through an advertising channel indexin use. After the advertising PDU is transmitted through an advertisingchannel index in use, the advertising event may be terminated, or in acase in which the advertising device may need to secure a space forperforming other function, the advertising event may be terminatedearlier.

Scanning State

The LL enters the scanning state according to an instruction from thehost (stack). In the scanning state, the LL listens to advertisingchannel indices.

The scanning state includes two types: passive scanning and activescanning. Each of the scanning types is determined by the host.

Time for performing scanning or an advertising channel index are notdefined.

During the scanning state, the LL listens to an advertising channelindex in a scan window duration. A scan interval is defined as aninterval between start points of two continuous scan windows.

When there is no collision in scheduling, the LL should listen in orderto complete all the scan intervals of the scan window as instructed bythe host. In each scan window, the LL should scan other advertisingchannel index. The LL uses every available advertising channel index.

In the passive scanning, the LL only receives packets and cannottransmit any packet.

In the active scanning, the LL performs listening in order to be reliedon an advertising PDU type for requesting advertising PDUs andadvertising device-related supplemental information from the advertisingdevice.

Initiating State

The LL enters the initiating state according to an instruction from thehost (stack).

When the LL is in the initiating state, the LL performs listening onadvertising channel indices.

During the initiating state, the LL listens to an advertising channelindex during the scan window interval.

Connection State

When the device performing a connection state, that is, when theinitiating device transmits a CONNECT_REQ PDU to the advertising deviceor when the advertising device receives a CONNECT_REQ PDU from theinitiating device, the LL enters a connection state.

It is considered that a connection is generated after the LL enters theconnection state. However, it is not necessary to consider that theconnection should be established at a point in time at which the LLenters the connection state. The only difference between a newlygenerated connection and an already established connection is a LLconnection supervision timeout value.

When two devices are connected, the two devices play different roles.

An LL serving as a master is termed a master, and an LL serving as aslave is termed a slave. The master adjusts a timing of a connectingevent, and the connecting event refers to a point in time at which themaster and the slave are synchronized.

Hereinafter, packets defined in an Bluetooth interface will be brieflydescribed. BLE devices use packets defined as follows.

Packet Format

The LL has only one packet format used for both an advertising channelpacket and a data channel packet.

Each packet includes four fields of a preamble, an access address, aPDU, and a CRC.

When one packet is transmitted in an advertising physical channel, thePDU may be an advertising channel PDU, and when one packet istransmitted in a data physical channel, the PDU may be a data channelPDU.

Advertising Channel PDU

An advertising channel PDU has a 16-bit header and payload havingvarious sizes.

A PDU type field of the advertising channel PDU included in the heaterindicates PDU types defined in Table 3 below.

TABLE 3 PDU Type Packet Name 0000 ADV_IND 0001 ADV_DIRECT_IND 0010ADV_NONDIRECT_IND 0011 SCAN_REQ 0100 SCAN_RSP 0101 CONNECT_REQ 0110ADV_SCAN_IND 0111-1111 Reserved

Advertising PDU

The following advertising channel PDU types are termed advertising PDUsand used in a specific event.

ADV_IND: Connectable undirected advertising event

ADV_DIRECT_IND: Connectable directed advertising event

ADV_NONCONN_IND: Unconnectable undirected advertising event

ADV_SCAN_IND: Scannable undirected advertising event

The PDUs are transmitted from the LL in an advertising state, andreceived by the LL in a scanning state or in an initiating state.

Scanning PDU

The following advertising channel DPU types are termed scanning PDUs andare used in a state described hereinafter.

SCAN_REQ: Transmitted by the LL in a scanning state and received by theLL in an advertising state.

SCAN_RSP: Transmitted by the LL in the advertising state and received bythe LL in the scanning state.

Initiating PDU

The following advertising channel PDU type is termed an initiating PDU.

CONNECT_REQ: Transmitted by the LL in the initiating state and receivedby the LL in the advertising state.

Data Channel PDU

The data channel PDU may include a message integrity check (MIC) fieldhaving a 16-bit header and payload having various sizes.

The procedures, states, and packet formats in the BLE technologydiscussed above may be applied to perform the methods proposed in thepresent disclosure.

Referring to FIG. 4a , The load (455) may correspond to a battery. Thebattery may store energy by using the power that is being outputted fromthe power pick-up unit (210). Meanwhile, the battery is not mandatorilyrequired to be included in the mobile device (450). For example, thebattery may be provided as a detachable external feature. As anotherexample, the wireless power receiver may include an operating means thatmay execute diverse functions of the electronic device instead of thebattery.

As shown in the drawing, although the mobile device (450) is illustratedto be included in the wireless power receiver (200) and the base station(400) is illustrated to be included in the wireless power transmitter(100), in a broader meaning, the wireless power receiver (200) may beidentified (or regarded) as the mobile device (450), and the wirelesspower transmitter (100) may be identified (or regarded) as the basestation (400).

When the communication/control circuit 120 and the communication/controlcircuit 220 include Bluetooth or Bluetooth LE as an OOB communicationmodule or a short-range communication module in addition to the IBcommunication module, the wireless power transmitter 100 including thecommunication/control circuit 120 and the wireless power receiver 200including the communication/control circuit 220 may be represented by asimplified block diagram as shown in FIG. 4 c.

FIG. 4c is a block diagram illustrating a wireless power transmissionsystem using BLE communication according to an example, and FIG. 4d is ablock diagram illustrating a wireless power transmission system usingBLE communication according to another example.

Referring to FIG. 4c , the wireless power transmitter 100 includes apower conversion circuit 110 and a communication/control circuit 120.The communication/control circuit 120 includes an in-band communicationmodule 121 and a BLE communication module 122.

Meanwhile, the wireless power receiver 200 includes a power pickupcircuit 210 and a communication/control circuit 220. Thecommunication/control circuit 220 includes an in-band communicationmodule 221 and a BLE communication module 222.

In one aspect, the BLE communication modules 122 and 222 perform thearchitecture and operation according to FIG. 4B. For example, the BLEcommunication modules 122 and 222 may be used to establish a connectionbetween the wireless power transmitter 100 and the wireless powerreceiver 200 and exchange control information and packets necessary forwireless power transfer.

In another aspect, the communication/control circuit 120 may beconfigured to operate a profile for wireless charging. Here, the profilefor wireless charging may be GATT using BLE transmission.

Meanwhile, the communication/control circuits 120 and 220 respectivelyinclude only in-band communication modules 121 and 221 as like FIG. 4d ,and the BLE communication modules 122 and 222 may be provided to beseparated from the communication/control circuits 120 and 220.

Hereinafter, the coil or coil unit includes a coil and at least onedevice being approximate to the coil, and the coil or coil unit may alsobe referred to as a coil assembly, a coil cell, or a cell.

Hereinafter, the coil or coil unit includes a coil and at least onedevice being approximate to the coil, and the coil or coil unit may alsobe referred to as a coil assembly, a coil cell, or a cell.

FIG. 5 is a state transition diagram for describing a wireless powertransfer procedure.

Referring to FIG. 5, the power transfer (or transfer) from the wirelesspower transmitter to the wireless power receiver according to anexemplary embodiment of the present disclosure may be broadly dividedinto a selection phase (510), a ping phase (520), an identification andconfiguration phase (530), a negotiation phase (540), a calibrationphase (550), a power transfer phase (560), and a renegotiation phase(570).

If a specific error or a specific event is detected when the powertransfer is initiated or while maintaining the power transfer, theselection phase (510) may include a shifting phase (or step)—referencenumerals S501, S502, S504, S508, S510, and S512. Herein, the specificerror or specific event will be specified in the following description.Additionally, during the selection phase (510), the wireless powertransmitter may monitor whether or not an object exists on an interfacesurface. If the wireless power transmitter detects that an object isplaced on the interface surface, the process step may be shifted to theping phase (520). During the selection phase (510), the wireless powertransmitter may transmit an analog ping of an extremely short pulse, andmay detect whether or not an object exists within an active area of theinterface surface based on a current change in the transmitting coil orthe primary coil.

In case an object is sensed (or detected) in the selection phase (510),the wireless power transmitter may measure a quality factor of awireless power resonance circuit (e.g., power transfer coil and/orresonance capacitor). According to the exemplary embodiment of thepresent disclosure, during the selection phase (510), the wireless powertransmitter may measure the quality factor in order to determine whetheror not a foreign object exists in the charging area along with thewireless power receiver. In the coil that is provided in the wirelesspower transmitter, inductance and/or components of the series resistancemay be reduced due to a change in the environment, and, due to suchdecrease, a value of the quality factor may also be decreased. In orderto determine the presence or absence of a foreign object by using themeasured quality factor value, the wireless power transmitter mayreceive from the wireless power receiver a reference quality factorvalue, which is measured in advance in a state where no foreign objectis placed within the charging area. The wireless power transmitter maydetermine the presence or absence of a foreign object by comparing themeasured quality factor value with the reference quality factor value,which is received during the negotiation phase (540). However, in caseof a wireless power receiver having a low reference quality factorvalue—e.g., depending upon its type, purpose, characteristics, and soon, the wireless power receiver may have a low reference quality factorvalue—in case a foreign object exists, since the difference between thereference quality factor value and the measured quality factor value issmall (or insignificant), a problem may occur in that the presence ofthe foreign object cannot be easily determined. Accordingly, in thiscase, other determination factors should be further considered, or thepresent or absence of a foreign object should be determined by usinganother method.

According to another exemplary embodiment of the present disclosure, incase an object is sensed (or detected) in the selection phase (510), inorder to determine whether or not a foreign object exists in thecharging area along with the wireless power receiver, the wireless powertransmitter may measure the quality factor value within a specificfrequency area (e.g., operation frequency area). In the coil that isprovided in the wireless power transmitter, inductance and/or componentsof the series resistance may be reduced due to a change in theenvironment, and, due to such decrease, the resonance frequency of thecoil of the wireless power transmitter may be changed (or shifted). Morespecifically, a quality factor peak frequency that corresponds to afrequency in which a maximum quality factor value is measured within theoperation frequency band may be moved (or shifted).

In the ping phase (520), if the wireless power transmitter detects thepresence of an object, the transmitter activates (or Wakes up) areceiver and transmits a digital ping for identifying whether or not thedetected object corresponds to the wireless power receiver. During theping phase (520), if the wireless power transmitter fails to receive aresponse signal for the digital ping—e.g., a signal intensitypacket—from the receiver, the process may be shifted back to theselection phase (510). Additionally, in the ping phase (520), if thewireless power transmitter receives a signal indicating the completionof the power transfer—e.g., charging complete packet—from the receiver,the process may be shifted back to the selection phase (510).

If the ping phase (520) is completed, the wireless power transmitter mayshift to the identification and configuration phase (530) foridentifying the receiver and for collecting configuration and statusinformation.

In the identification and configuration phase (530), if the wirelesspower transmitter receives an unwanted packet (i.e., unexpected packet),or if the wireless power transmitter fails to receive a packet during apredetermined period of time (i.e., out of time), or if a packettransmission error occurs (i.e., transmission error), or if a powertransfer contract is not configured (i.e., no power transfer contract),the wireless power transmitter may shift to the selection phase (510).

The wireless power transmitter may determine whether it is necessary toenter the negotiation step 540 based on the negotiation field value ofthe configuration packet received in the identification andconfiguration step 530. As a result of the check, if negotiation isnecessary, the wireless power transmitter may enter a negotiation step540 to perform a predetermined Foreign Object Detection (FOD) procedure.On the other hand, as a result of the check, if negotiation is notnecessary, the wireless power transmitter may directly enter the powertransmission step 560. If the line power transmitter and receiversupport out-band communication such as BLE, in the identification andconfiguration step 530, the out-band communication module of thewireless power transmitter receives the ID or identification packet ofthe wireless power receiver, and sends and receives messages related toconfigurations necessary for power transmission.

In the negotiation phase (540), the wireless power transmitter mayreceive a Foreign Object Detection (FOD) status packet that includes areference quality factor value. Or, the wireless power transmitter mayreceive an FOD status packet that includes a reference peak frequencyvalue. Alternatively, the wireless power transmitter may receive astatus packet that includes a reference quality factor value and areference peak frequency value. At this point, the wireless powertransmitter may determine a quality coefficient threshold value for FOdetection based on the reference quality factor value. The wirelesspower transmitter may determine a peak frequency threshold value for FOdetection based on the reference peak frequency value.

The wireless power transmitter may detect the presence or absence of anFO in the charging area by using the determined quality coefficientthreshold value for FO detection and the currently measured qualityfactor value (i.e., the quality factor value that was measured beforethe ping phase), and, then, the wireless power transmitter may controlthe transmitted power in accordance with the FO detection result. Forexample, in case the FO is detected, the power transfer may be stopped.However, the present disclosure will not be limited only to this.

The wireless power transmitter may detect the presence or absence of anFO in the charging area by using the determined peak frequency thresholdvalue for FO detection and the currently measured peak frequency value(i.e., the peak frequency value that was measured before the pingphase), and, then, the wireless power transmitter may control thetransmitted power in accordance with the FO detection result. Forexample, in case the FO is detected, the power transfer may be stopped.However, the present disclosure will not be limited only to this.

In case the FO is detected, the wireless power transmitter may return tothe selection phase (510). Conversely, in case the FO is not detected,the wireless power transmitter may proceed to the calibration phase(550) and may, then, enter the power transfer phase (560). Morespecifically, in case the FO is not detected, the wireless powertransmitter may determine the intensity of the received power that isreceived by the receiving end during the calibration phase (550) and maymeasure power loss in the receiving end and the transmitting end inorder to determine the intensity of the power that is transmitted fromthe transmitting end. In other words, during the calibration phase(550), the wireless power transmitter may estimate the power loss basedon a difference between the transmitted power of the transmitting endand the received power of the receiving end. The wireless powertransmitter according to the exemplary embodiment of the presentdisclosure may calibrate the threshold value for the FOD by applying theestimated power loss.

When the wireless power transmitter and the receiver support out-bandcommunication such as BLE, in the correction step 550, the in-bandcommunication modules of the wireless power transmitter and the wirelesspower receiver may exchange information necessary for a foreign materialdetection algorithm according to the charging profile.

In addition, when the wireless power transmitter and the receiversupport out-band communication such as BLE, in the negotiation step 540,the connected BLE communication may be used to exchange and negotiateinformation related to wireless power transmission. And when theexchange of information related to wireless power transmission throughBLE during the negotiation step 540 is completed, the out-bandcommunication module may notify the in-band communication module (orcontrol circuit) of this and transmit a start power transfer messageinstructing the start of wireless power transfer to the in-bandcommunication module (or control circuit).

In the power transfer phase (560), in case the wireless powertransmitter receives an unwanted packet (i.e., unexpected packet), or incase the wireless power transmitter fails to receive a packet during apredetermined period of time (i.e., time-out), or in case a violation ofa predetermined power transfer contract occurs (i.e., power transfercontract violation), or in case charging is completed, the wirelesspower transmitter may shift to the selection phase (510).

Additionally, in the power transfer phase (560), in case the wirelesspower transmitter is required to reconfigure the power transfer contractin accordance with a status change in the wireless power transmitter,the wireless power transmitter may shift to the renegotiation phase(570). At this point, if the renegotiation is successfully completed,the wireless power transmitter may return to the power transfer phase(560).

In this embodiment, the calibration step 550 and the power transferphase 560 are divided into separate steps, but the calibration step 550may be integrated into the power transfer phase 560. In this case,operations in the calibration step 550 may be performed in the powertransfer phase 560.

The above-described power transfer contract may be configured based onthe status and characteristic information of the wireless powertransmitter and receiver. For example, the wireless power transmitterstatus information may include information on a maximum amount oftransmittable power, information on a maximum number of receivers thatmay be accommodated, and so on. And, the receiver status information mayinclude information on the required power, and so on.

FIG. 6 is a diagram illustrating a power control method according to anembodiment.

As shown in FIG. 6, in the power transfer phase (560), by alternatingthe power transfer and/or reception and communication, the wirelesspower transmitter (100) and the wireless power receiver (200) maycontrol the amount (or size) of the power that is being transferred. Thewireless power transmitter and the wireless power receiver operate at aspecific control point. The control point indicates a combination of thevoltage and the electric current that are provided from the output ofthe wireless power receiver, when the power transfer is performed.

More specifically, the wireless power receiver selects a desired controlpoint, a desired output current/voltage, a temperature at a specificlocation of the mobile device, and so on, and additionally determines anactual control point at which the receiver is currently operating. Thewireless power receiver calculates a control error value by using thedesired control point and the actual control point, and, then, thewireless power receiver may transmit the calculated control error valueto the wireless power transmitter as a control error packet.

Also, the wireless power transmitter may configure/control a newoperating point—amplitude, frequency, and duty cycle—by using thereceived control error packet, so as to control the power transfer.Therefore, the control error packet may be transmitted/received at aconstant time interval during the power transfer phase, and, accordingto the exemplary embodiment, in case the wireless power receiverattempts to reduce the electric current of the wireless powertransmitter, the wireless power receiver may transmit the control errorpacket by setting the control error value to a negative number. And, incase the wireless power receiver intends to increase the electriccurrent of the wireless power transmitter, the wireless power receivertransmit the control error packet by setting the control error value toa positive number. During the induction mode, by transmitting thecontrol error packet to the wireless power transmitter as describedabove, the wireless power receiver may control the power transfer.

In the resonance mode, which will hereinafter be described in detail,the device may be operated by using a method that is different from theinduction mode. In the resonance mode, one wireless power transmittershould be capable of serving a plurality of wireless power receivers atthe same time. However, in case of controlling the power transfer justas in the induction mode, since the power that is being transferred iscontrolled by a communication that is established with one wirelesspower receiver, it may be difficult to control the power transfer ofadditional wireless power receivers. Therefore, in the resonance modeaccording to the present disclosure, a method of controlling the amountof power that is being received by having the wireless power transmittercommonly transfer (or transmit) the basic power and by having thewireless power receiver control its own resonance frequency.Nevertheless, even during the operation of the resonance mode, themethod described above in FIG. 6 will not be completely excluded. And,additional control of the transmitted power may be performed by usingthe method of FIG. 6.

FIG. 7 is a block diagram of a wireless power transmitter according toanother exemplary embodiment of the present disclosure. This may belongto a wireless power transfer system that is being operated in themagnetic resonance mode or the shared mode. The shared mode may refer toa mode performing a several-for-one (or one-to-many) communication andcharging between the wireless power transmitter and the wireless powerreceiver. The shared mode may be implemented as a magnetic inductionmethod or a resonance method.

Referring to FIG. 7, the wireless power transmitter (700) may include atleast one of a cover (720) covering a coil assembly, a power adapter(730) supplying power to the power transmitter (740), a powertransmitter (740) transmitting wireless power, and a user interface(750) providing information related to power transfer processing andother related information. Most particularly, the user interface (750)may be optionally included or may be included as another user interface(750) of the wireless power transmitter (700).

The power transmitter (740) may include at least one of a coil assembly(760), an impedance matching circuit (770), an inverter (780), acommunication unit (790), and a control unit (710).

The coil assembly (760) includes at least one primary coil generating amagnetic field. And, the coil assembly (760) may also be referred to asa coil cell.

The impedance matching circuit (770) may provide impedance matchingbetween the inverter and the primary coil(s). The impedance matchingcircuit (770) may generate resonance from a suitable frequency thatboosts the electric current of the primary coil(s). In a multi-coilpower transmitter (740), the impedance matching circuit may additionallyinclude a multiplex that routes signals from the inverter to a subset ofthe primary coils. The impedance matching circuit may also be referredto as a tank circuit.

The impedance matching circuit (770) may include a capacitor, aninductor, and a switching device that switches the connection betweenthe capacitor and the inductor. The impedance matching may be performedby detecting a reflective wave of the wireless power that is beingtransferred (or transmitted) through the coil assembly (760) and byswitching the switching device based on the detected reflective wave,thereby adjusting the connection status of the capacitor or the inductoror adjusting the capacitance of the capacitor or adjusting theinductance of the inductor. In some cases, the impedance matching may becarried out even though the impedance matching circuit (770) is omitted.This specification also includes an exemplary embodiment of the wirelesspower transmitter (700), wherein the impedance matching circuit (770) isomitted.

For example, the impedance matching circuit 770 may be composed of atotal of four inverters for power conversion for each coil, and receivesa PWM signal from the control circuit 710. Impedance matching circuit770 is driven by passing a signal to the inverter through two 4-channellogic switches.

The inverter (780) may convert a DC input to an AC signal. The inverter(780) may be operated as a half-bridge inverter or a full-bridgeinverter in order to generate a pulse wave and a duty cycle of anadjustable frequency. Additionally, the inverter may include a pluralityof stages in order to adjust input voltage levels.

The communication unit (790) may perform communication with the powerreceiver. The power receiver performs load modulation in order tocommunicate requests and information corresponding to the powertransmitter. Therefore, the power transmitter (740) may use thecommunication unit (790) so as to monitor the amplitude and/or phase ofthe electric current and/or voltage of the primary coil in order todemodulate the data being transmitted from the power receiver.

The communication circuit 790 may include any one or both of an in-bandcommunication module and an out-band communication module. Thecommunication circuit 790 is configured to search for a wireless powerreceiver or to transmit data to the wireless power receiver. Here, thecommunication circuit 790 may be configured to perform a procedurerelated to authentication of the wireless power receiver. Here,authentication includes Qi authentication. For example, thecommunication circuit 790 may receive authentication-related informationfrom the wireless power receiver or transmit authentication-relatedinformation to the wireless power receiver.

Additionally, the power transmitter (740) may control the output powerto that the data may be transferred through the communication unit (790)by using a Frequency Shift Keying (FSK) method, and so on.

The control unit (710) may control communication and power transfer (ordelivery) of the power transmitter (740). The control unit (710) maycontrol the power transfer by adjusting the above-described operatingpoint. The operating point may be determined by, for example, at leastany one of the operation frequency, the duty cycle, and the inputvoltage.

The communication unit (790) and the control unit (710) may each beprovided as a separate unit/device/chipset or may be collectivelyprovided as one unit/device/chipset.

FIG. 8 is a block diagram of an apparatus for receiving wireless poweraccording to another embodiment. This may belong to a wireless powertransmission system of a magnetic resonance method or a shared mode.

Referring to FIG. 8, the wireless power receiver (800) may include atleast one of a user interface (820) providing information related topower transfer processing and other related information, a powerreceiver (830) receiving wireless power, a load circuit (840), and abase (850) supporting and covering the coil assembly. Most particularly,the user interface (820) may be optionally included or may be includedas another user interface (820) of the wireless power receiver (800).

The power receiver (830) may include at least one of a power converter(860), an impedance matching circuit (870), a coil assembly (880), acommunication unit (890), and a control unit (810).

The power converter (860) may convert the AC power that is received fromthe secondary coil to a voltage and electric current that are suitablefor the load circuit. According to an exemplary embodiment, the powerconverter (860) may include a rectifier. The rectifier may rectify thereceived wireless power and may convert the power from an alternatingcurrent (AC) to a direct current (DC). The rectifier may convert thealternating current to the direct current by using a diode or atransistor, and, then, the rectifier may smooth the converted current byusing the capacitor and resistance. Herein, a full-wave rectifier, ahalf-wave rectifier, a voltage multiplier, and so on, that areimplemented as a bridge circuit may be used as the rectifier.Additionally, the power converter may adapt a reflected impedance of thepower receiver.

The impedance matching circuit (870) may provide impedance matchingbetween a combination of the power converter (860) and the load circuit(840) and the secondary coil. According to an exemplary embodiment, theimpedance matching circuit may generate a resonance of approximately 100kHz, which may reinforce the power transfer. The impedance matchingcircuit (870) may include a capacitor, an inductor, and a switchingdevice that switches the combination of the capacitor and the inductor.The impedance matching may be performed by controlling the switchingdevice of the circuit that configured the impedance matching circuit(870) based on the voltage value, electric current value, power value,frequency value, and so on, of the wireless power that is beingreceived. Alternatively, the impedance matching circuit 870 may becomposed of a total of four inverters for power conversion for eachcoil, and receives a PWM signal from the control circuit 810. Impedancematching circuit 870 is driven by passing a signal to the inverterthrough two 4-channel logic switches.

In some cases, the impedance matching may be carried out even though theimpedance matching circuit (870) is omitted. This specification alsoincludes an exemplary embodiment of the wireless power receiver (200),wherein the impedance matching circuit (870) is omitted.

The coil assembly (880) includes at least one secondary coil, and,optionally, the coil assembly (880) may further include an elementshielding the metallic part of the receiver from the magnetic field.

The communication unit (890) may perform load modulation in order tocommunicate requests and other information to the power transmitter. Forthis, the power receiver (830) may perform switching of the resistanceor capacitor so as to change the reflected impedance.

The communication circuit 890 may include any one or both of an in-bandcommunication module and an out-band communication module. Thecommunication circuit 890 is configured to search for a wireless powertransmitter or to transmit data to the wireless power transmitter. Here,the communication circuit 890 may be configured to perform a procedurerelated to authentication of the wireless power transmitter. Here,authentication includes Qi authentication. For example, thecommunication circuit 890 may receive authentication-related informationfrom or transmit to the wireless power transmitter.

The control unit (810) may control the received power. For this, thecontrol unit (810) may determine/calculate a difference between anactual operating point and a target operating point of the powerreceiver (830). Thereafter, by performing a request for adjusting thereflected impedance of the power transmitter and/or for adjusting anoperating point of the power transmitter, the difference between theactual operating point and the target operating point may beadjusted/reduced. In case of minimizing this difference, an optimalpower reception may be performed. The control circuit 810 may beconfigured to perform a procedure related to authentication of thewireless power receiver. Here, authentication includes Qiauthentication.

The communication unit (890) and the control unit (810) may each beprovided as a separate device/chipset or may be collectively provided asone device/chipset.

FIG. 9 is a diagram illustrating a communication frame structureaccording to an embodiment. This may be a communication frame structurein a shared mode.

Referring to FIG. 9, in the shared mode, different forms of frames maybe used along with one another. For example, in the shared mode, aslotted frame having a plurality of slots, as shown in (A), and a freeformat frame that does not have a specified format, as shown in (B), maybe used. More specifically, the slotted frame corresponds to a frame fortransmitting short data packets from the wireless power receiver (200)to the wireless power transmitter (100). And, since the free formatframe is not configured of a plurality of slots, the free format framemay correspond to a frame that is capable of performing transmission oflong data packets.

Meanwhile, the slotted frame and the free format frame may be referredto other diverse terms by anyone skilled in the art. For example, theslotted frame may be alternatively referred to as a channel frame, andthe free format frame may be alternatively referred to as a messageframe.

More specifically, the slotted frame may include a sync patternindicating the starting point (or beginning) of a slot, a measurementslot, nine slots, and additional sync patterns each having the same timeinterval that precedes each of the nine slots.

Herein, the additional sync pattern corresponds to a sync pattern thatis different from the sync pattern that indicates the starting point ofthe above-described frame. More specifically, the additional syncpattern does not indicate the starting point of the frame but mayindicate information related to the neighboring (or adjacent) slots(i.e., two consecutive slots positioned on both sides of the syncpattern).

Among the nine slots, each sync pattern may be positioned between twoconsecutive slots. In this case, the sync pattern may provideinformation related to the two consecutive slots.

Additionally, the nine slots and the sync patterns being provided beforeeach of the nine slots may have the same time interval. For example, thenine slots may have a time interval of 50 ms. And, the nine syncpatterns may have a time length of 50 ms.

Meanwhile, the free format frame, as shown in (B) may not have aspecific format apart from the sync pattern indicating the startingpoint of the frame and the measurement slot. More specifically, the freeformat frame is configured to perform a function that is different fromthat of the slotted frame. For example, the free format frame may beused to perform a function of performing communication of long datapackets (e.g., additional owner information packets) between thewireless power transmitter and the wireless power receiver, or, in caseof a wireless power transmitter being configured of multiple coils, toperform a function of selecting any one of the coils.

Hereinafter, a sync pattern that is included in each frame will bedescribed in more detail with reference to the accompanying drawings.

FIG. 10 is a structure of a sync pattern according to an exemplaryembodiment of the present disclosure.

Referring to FIG. 10, the sync pattern may be configured of a preamble,a start bit, a response field, a type field, an info field, and a paritybit. In FIG. 10, the start bit is illustrated as ZERO.

More specifically, the preamble is configured of consecutive bits, andall of the bits may be set to 0. In other words, the preamble maycorrespond to bits for matching a time length of the sync pattern.

The number of bits configuring the preamble may be subordinate to theoperation frequency so that the length of the sync pattern may be mostapproximate to 50 ms but within a range that does not exceed 50 ms. Forexample, in case the operation frequency corresponds to 100 kHz, thesync pattern may be configured of two preamble bits, and, in case theoperation frequency corresponds to 105 kHz, the sync pattern may beconfigured of three preamble bits.

The start bit may correspond to a bit that follows the preamble, and thestart bit may indicate ZERO. The ZERO may correspond to a bit thatindicates a type of the sync pattern. Herein, the type of sync patternsmay include a frame sync including information that is related to aframe, and a slot sync including information of the slot. Morespecifically, the sync pattern may be positioned between consecutiveframes and may correspond to a frame sync that indicate a start of theframe, or the sync pattern may be positioned between consecutive slotsamong a plurality of slots configuring the frame and may correspond to async slot including information related to the consecutive slots.

For example, in case the ZERO is equal to 0, this may indicate that thecorresponding slot is a slot sync that is positioned in-between slots.And, in case the ZERO is equal to 1, this may indicate that thecorresponding sync pattern is a frame sync being located in-betweenframes.

A parity bit corresponds to a last bit of the sync pattern, and theparity bit may indicate information on a number of bits configuring thedata fields (i.e., the response field, the type field, and the infofield) that are included in the sync pattern. For example, in case thenumber of bits configuring the data fields of the sync patterncorresponds to an even number, the parity bit may be set to when, and,otherwise (i.e., in case the number of bits corresponds to an oddnumber), the parity bit may be set to 0.

The response field may include response information of the wirelesspower transmitter for its communication with the wireless power receiverwithin a slot prior to the sync pattern. For example, in case acommunication between the wireless power transmitter and the wirelesspower receiver is not detected, the response field may have a value of‘00’. Additionally, if a communication error is detected in thecommunication between the wireless power transmitter and the wirelesspower receiver, the response field may have a value of ‘01’. Thecommunication error corresponds to a case where two or more wirelesspower receivers attempt to access one slot, thereby causing collision tooccur between the two or more wireless power receivers.

Additionally, the response field may include information indicatingwhether or not the data packet has been accurately received from thewireless power receiver. More specifically, in case the wireless powertransmitter has denied the data packet, the response field may have avalue of “10” (10—not acknowledge (NAK)). And, in case the wirelesspower transmitter has confirmed the data packet, the response field mayhave a value of “11” (11—acknowledge (ACK)).

The type field may indicate the type of the sync pattern. Morespecifically, in case the sync pattern corresponds to a first syncpattern of the frame (i.e., as the first sync pattern, in case the syncpattern is positioned before the measurement slot), the type field mayhave a value of ‘1’, which indicates a frame sync.

Additionally, in a slotted frame, in case the sync pattern does notcorrespond to the first sync pattern of the frame, the type field mayhave a value of ‘0’, which indicates a slot sync.

Moreover, the information field may determine the meaning of its valuein accordance with the sync pattern type, which is indicated in the typefield. For example, in case the type field is equal to 1 (i.e., in casethe sync pattern type indicates a frame sync), the meaning of theinformation field may indicate the frame type. More specifically, theinformation field may indicate whether the current frame corresponds toa slotted frame or a free-format frame. For example, in case theinformation field is given a value of ‘00’, this indicates that thecurrent frame corresponds to a slotted frame. And, in case theinformation field is given a value of ‘01’, this indicates that thecurrent frame corresponds to a free-format frame.

Conversely, in case the type field is equal to 0 (i.e., in case the syncpattern type indicates a slot sync), the information field may indicatea state of a next slot, which is positioned after the sync pattern. Morespecifically, in case the next slot corresponds to a slot that isallocated (or assigned) to a specific wireless power receiver, theinformation field is given a value of ‘00’. In case the next slotcorresponds to a slot that is locked, so as to be temporarily used bythe specific wireless power receiver, the information field is given avalue of ‘01’. Alternatively, in case the next slot corresponds to aslot that may be freely used by a random wireless power receiver, theinformation field is given a value of ‘10’.

FIG. 11 shows operation statuses of a wireless power transmitter and awireless power receiver in a shared mode according to an exemplaryembodiment of the present disclosure.

Referring to FIG. 11, the wireless power receiver operating in theshared mode may be operated in any one of a selection phase (1100), anintroduction phase (1110), a configuration phase (1120), a negotiationphase (1130), and a power transfer phase (1140).

Firstly, the wireless power transmitter according to the exemplaryembodiment of the present disclosure may transmit a wireless powersignal in order to detect the wireless power receiver. Morespecifically, a process of detecting a wireless power receiver by usingthe wireless power signal may be referred to as an Analog ping.

Meanwhile, the wireless power receiver that has received the wirelesspower signal may enter the selection phase (1100). As described above,the wireless power receiver that has entered the selection phase (1100)may detect the presence or absence of an FSK signal within the wirelesspower signal.

In other words, the wireless power receiver may perform communication byusing any one of an exclusive mode and a shared mode in accordance withthe presence or absence of the FSK signal.

More specifically, in case the FSK signal is included in the wirelesspower signal, the wireless power receiver may operate in the sharedmode, and, otherwise, the wireless power receiver may operate in theexclusive mode.

In case the wireless power receiver operates in the shared mode, thewireless power receiver may enter the introduction phase (1110). In theintroduction phase (1110), the wireless power receiver may transmit acontrol information (CI) packet to the wireless power transmitter inorder to transmit the control information packet during theconfiguration phase, the negotiation phase, and the power transferphase. The control information packet may have a header and informationrelated to control. For example, in the control information packet, theheader may correspond to 0X53.

In the introduction phase (1110), the wireless power receiver performsan attempt to request a free slot for transmitting the controlinformation (CI) packet during the following configuration phase,negotiation phase, and power transfer phase. At this point, the wirelesspower receiver selects a free slot and transmits an initial CI packet.If the wireless power transmitter transmits an ACK as a response to thecorresponding CI packet, the wireless power receiver enters theconfiguration phase. If the wireless power transmitter transmits a NAKas a response to the corresponding CI packet, this indicates thatanother wireless power receiver is performing communication through theconfiguration and negotiation phase. In this case, the wireless powerreceiver re-attempts to perform a request for a free slot.

If the wireless power receiver receives an ACK as a response to the CIpacket, the wireless power receiver may determine the position of aprivate slot within the frame by counting the remaining sync slots up tothe initial frame sync. In all of the subsequent slot-based frames, thewireless power receiver transmits the CI packet through thecorresponding slot.

If the wireless power transmitter authorizes the entry of the wirelesspower receiver to the configuration phase, the wireless powertransmitter provides a locked slot series for the exclusive usage of thewireless power receiver. This may ensure the wireless power receiver toproceed to the configuration phase without any collision.

The wireless power receiver transmits sequences of data packets, such astwo identification data packets (IDHI and IDLO), by using the lockedslots. When this phase is completed, the wireless power receiver entersthe negotiation phase. During the negotiation state, the wireless powertransmitter continues to provide the locked slots for the exclusiveusage of the wireless power receiver. This may ensure the wireless powerreceiver to proceed to the negotiation phase without any collision.

The wireless power receiver transmits one or more negotiation datapackets by using the corresponding locked slot, and the transmittednegotiation data packet(s) may be mixed with the private data packets.Eventually, the corresponding sequence is ended (or completed) alongwith a specific request (SRQ) packet. When the corresponding sequence iscompleted, the wireless power receiver enters the power transfer phase,and the wireless power transmitter stops the provision of the lockedslots.

In the power transfer phase, the wireless power receiver performs thetransmission of a CI packet by using the allocated slots and thenreceives the power. The wireless power receiver may include a regulatorcircuit. The regulator circuit may be included in acommunication/control unit. The wireless power receiver mayself-regulate a reflected impedance of the wireless power receiverthrough the regulator circuit. In other words, the wireless powerreceiver may adjust the impedance that is being reflected for an amountof power that is requested by an external load. This may prevent anexcessive reception of power and overheating.

In the shared mode, (depending upon the operation mode) since thewireless power transmitter may not perform the adjustment of power as aresponse to the received CI packet, in this case, control may be neededin order to prevent an overvoltage state.

Hereinafter, a switching operation between in-band communication andout-band communication is referred to as a handover. In particular, theoperation in which the wireless power transmitter and the wireless powerreceiver switch from in-band communication to out-band communication iscalled handover to out-band, the operation in which the wireless powertransmitter and the wireless power receiver switch from out-bandcommunication to in-band communication is called handover to in-band.Out-band communication may include, for example, Bluetooth or BluetoothLow Energy (BLE), or NFC. The handover connection procedure may includea procedure for establishing an out-band communication connection whenthe out-band communication (i.e. BLE) module receives a handover messagefrom the in-band communication module. Here, the handover message may bea message instructing the in-band communication module (or control unit)to initiate a wireless connection for exchanging information related towireless power transmission to the out-band communication module.

In order for out-band communication to be applied to the wireless powertransmission system, it needs to be modified according to the uniquecharacteristics of the wireless power transmission system. For example,in consideration of the characteristics of information (ex. whether itis urgent information, whether it is only transmitted when the status ischanged, whether large amounts of information need to be exchanged in ashort time, etc.) exchanged between the wireless power transmitter andthe wireless power receiver, the message type, format, and proceduresaccording to the existing out-band communication should be redesigned.Like this, by defining procedures for setting information, controlinformation, management information and their exchange regardingwireless power transmission as an out-band communication protocol,various applications of wireless power can be supported.

Hereinafter, in this specification, out-band communication will bespecifically described as BLE by way of example. However, in theembodiments described based on BLE, it is apparent to those skilled inthe art that embodiments in which BLE is replaced with other out-bandcommunication also fall within the technical spirit of the presentdisclosure.

FIG. 12 is a flowchart illustrating a method of exchanging wirelesscharging-related information in an out-band or in-band by a wirelesspower transmitter and a wireless power receiver according to anembodiment, and FIG. 13 is a flowchart illustrating a method by whichthe wireless power receiver notifies the wireless power transmitter ofan error according to an embodiment.

In FIGS. 12 and 13, PTU means a power transfer circuit, and PRU means apower receiving circuit. The information transmission method in FIGS. 12and 13 may be a method according to Alliance for Wireless Power (A4WP)or AFA standard technology.

Referring to FIG. 12 first, when the power of the PTU is turned on, thePTU enters a power save state through a configuration state that is aninitial configuration stage.

In the power save state, the PTU transmits a power beacon to the PRU(S1200). The power save state is maintained until the PTU receives anadvertisement from the PRU.

When the power of the PRU is turned on and booted, the PRU sends a PRUadvertisement (S1210). The PTU which receives the PRU advertisemententers a low power state.

When receiving an Advertising packet (ADV) for discovery from the BLEmodule of the PRU (S1220), in the low power state, the BLE module of thePTU transmits a connection request to the PRU to establish a BLEconnection with the PRU (S1230).

In a state where BLE communication between the PTU and the PRU ispossible, the PTU reads the PRU static parameters of the PRU through aread request and a read response message (S1240, S1250). Here, the PRUstatic parameter includes state information of the PRU.

In addition, the PTU transmits PTU static parameter informationcontaining its capabilities information to the PRU through a writerequest message (S1260).

After exchanging static parameter information, the PTU periodicallyreceives PRU dynamic parameter information measured in the PRU through aread request and a read response (S1270, S1280). Here, the PRU dynamicparameters include voltage information, current information, temperatureinformation, and the like.

When the PTU informs the PRU to charge or controls the permission of thePRU, the PRU may perform PRU control using a write request (S1290).

Referring to FIG. 13, the PTU may control the PTU through a writerequest in the power transmission state (S1300). In addition, the PRUdynamic parameter may be received from the PRU through the read requestmessage and the read response message (S1310 to S1340). The PTU mayacquire the PRU dynamic parameters at a period of 250 ms.

If this operation is repeated and the PRU detects an error such as overvoltage protection (OVP), the PTU transmits a PRU alert to the PTUthrough an indication message (S1350). When the PTU receives anindication message including a PRU alert, it enters the latch faultstate.

FIG. 14 is a diagram illustrating a situation in which a wireless powertransmitter provides a power transmission service to a plurality ofwireless power receivers, and FIG. 15 is a diagram illustrating anoperation of a Bluetooth communication device.

As shown in FIG. 14, a wireless power transmitter including a multi-coilmay be connected to a plurality of wireless power receivers using a BLEmodule as an out-band communication module.

Meanwhile, referring to FIG. 15, the Bluetooth communication standarddefines an advertiser role that periodically broadcasts an advertisementpacket including device information (i.e. MAC address, device name,identifier, etc.). In addition, the Bluetooth communication standarddefines the role of a scanner that searches for nearby advertiserdevices.

Before Bluetooth connection, the advertiser transmits an advertisingpacket to the scanner through the advertising channel, and afterBluetooth connection, the advertiser device plays a slave role. Thedevice, which was performing the scanner role, performs the initiatorrole when connecting with the Bluetooth, and then performs the masterrole after connecting with the Bluetooth. Slave and master exchange datathrough data channels.

The wireless power transmitter may be connected to a plurality ofwireless power receivers using a BLE module as an out-band communicationmodule. In this case, the wireless power transmitter may operate as ascanner and then operate as a master after being connected to thewireless power receiver to manage the wireless power receiver.Alternatively, the wireless power transmitter may operate as anadvertiser and then operate as a slave after being connected to thewireless power receiver to communicate with the wireless powerreceivers. Therefore, it is necessary to clearly define the operationmethods of the wireless power transmitter and the wireless powerreceiver for each of the above scenarios.

FIG. 16 is a diagram for explaining terms and procedures used in thepresent embodiment.

Hereinafter, a scan rule and scan procedure, a mode for reporting a scanresult, and messages and parameters used in the scan procedure used inthis embodiment for out-band communication will be described in detail.Here, the scan rule is to determine who performs the scan between thewireless power transmitter and at least one wireless power receiver. Thecomponents and features necessary to describe the present disclosure aresummarized by category as follows.

Scan record: The scan record may mean information about a result ofsearching for a peripheral device using BLE (e.g. device name,identifier, address, service information, etc.). If there are twoout-band communication modules of the device having the correspondinginformation, sharing is possible through the scan record sharingmessage.

Scheduling sharing procedure: When the wireless power receiver operatingas the master receives a collision (or retry request) notification fromthe wireless power transmitter, the wireless power receiver and thewireless power transmitter may perform scheduling sharing and changeprocedures.

Qi system device identification and service ID: Qi system deviceidentification and service ID may refer to parameters includinginformation indicating that a Qi system related service is provided.Here, the Qi system device may mean a device that has been certified fora specific standard (e.g., Qi). When the wireless power receiverreceives information about the Qi system device identification andservice ID, the wireless power receiver may ignore the information orperform a separate process.

Mode Interval: When the wireless power transmitter operates as a scanneror master (that is, when the wireless power receiver operates as anadvertiser or slave), the wireless power receiver needs to operate as ascanner or a master for other Bluetooth operations (e.g., connectionwith a nearby smart band, etc.) regardless of the wireless powertransmission system. Therefore, in this case, the mode (or role) of thewireless power receiver (or Bluetooth module) may be changed. A periodin which the mode (or role) is changed in this way may be defined as amode interval. The wireless power transmitter and the wireless powerreceiver may exchange and share information about the mode intervalbased on the mode interval sharing message.

In this embodiment, the wireless power transmitter and the wirelesspower receiver may be defined to operate according to the procedureaccording to FIG. 16 throughout the power transmission procedure andcommunication procedure.

Referring to FIG. 16, the first device and the second device operate ina specific state (State). For example, the specific state may include aconnection state. Here, the connection state may mean a state in which acommunication link between the first device and the second device isestablished. In this case, the first device may be a wireless powertransmitter and the second device may be a wireless power receiver.Alternatively, the first device may be a wireless power receiver and thesecond device may be a wireless power transmitter. Alternatively, thefirst device may be a first wireless power receiver and the seconddevice may be a second wireless power receiver.

In the first state, the first device or the second device enters aspecific mode (Mode). Here, the specific mode may include a selectionmode, an identification and configuration mode, a negotiation mode, acorrection mode, a power transmission mode, a scan acceptable mode, andthe like. That is, each phase in FIGS. 5 and 11 may be called a mode.

In a specific mode, a procedure for performing a specific function ofwireless power transmission or communication between the first deviceand the second device may be performed (Procedure). For example, theprocedure may include exchanging a first message and a second message.Each message may include parameters that the wireless power transmitteror wireless power receiver wants to transmit to the counterpart device.

Hereinafter, a method of applying the role of Bluetooth suitable for awireless power transmitter and a wireless power receiver, and a relatedstack structure will be described.

FIG. 17 is a diagram showing the structure of roles of a wireless powertransmitter and a wireless power receiver according to an example, andFIG. 18 is a hardware block diagram of the wireless power receiveraccording to an example.

Referring to FIG. 17, the wireless power transmitter (PTx) may operateas an advertiser before being connected to the wireless power receiver,and may operate as a slave (GATT server) after being connected to thewireless power receiver. The wireless power receivers (PRxs) may operateas a scanner before being connected to the wireless power transmitter,and may operate as a master (GATT client) after being connected to thewireless power transmitter.

In this case, since a wireless power receiver such as a low-power device(e.g., a mobile phone) operates as a scanner in many use-cases using theBLE function, when the wireless power receiver operates as in the rolestructure shown in FIG. 17, it is suitable to reuse the existingBluetooth hardware and software, and also it is possible to avoidcollision with the existing role.

As shown in FIG. 18, the wireless power receiver does not use adedicated Bluetooth module for a wireless power transmission system(e.g., Qi system) for wireless power transmission, and the existingBluetooth module of the mobile phone can be used.

In this case, the wireless power receiver of the wireless powertransmission system can output 5 to 5.5V, the out-band communicationmodule (i.e., the Bluetooth module) can perform and operate by receivingthe voltage of 5 to 5.5V as an input voltage. At this time, if theexisting operation method of the wireless power receiver operates as ascanner/master, a software stack configured like a protocol stack in thedrawing may be reused.

FIG. 19 is a diagram illustrating a communication link between devicesin the role structure according to FIG. 17.

Referring to FIG. 19, in the role structure of FIG. 17, since thewireless power transmitter operates as a slave, when the wireless powertransmitter is connected to two wireless power receivers, the wirelesspower transmitter cannot manage the two Bluetooth links. Therefore, asshown in FIG. 19, when the first wireless power receiver communicateswith the wireless power transmitter at a cycle of 11.25 ms and thesecond wireless power receiver communicates with the wireless powertransmitter at a cycle of 15 ms, A collision may occur between a packetexchanged by the wireless power transmitter with the first wirelesspower receiver and a packet exchanged by the wireless power transmitterwith the second wireless power receiver. This is because only the mastercan perform a role (e.g., scheduling, etc.) for managing a plurality ofBluetooth links. That is, the wireless power transmitter cannot performthe scheduling operation for the first wireless power receiver and thesecond wireless power receiver in the time dimension. Accordingly, whena packet collision occurs during communication with a plurality ofwireless power receivers, the wireless power transmitter must requestretransmission.

In order to effectively manage this, according to this embodiment, afirst connection parameter for out-band communication between thewireless power transmitter and the first wireless power receiver and asecond connection parameter for out-band communication between thewireless power transmitter and the second wireless power may beadjusted. As an example, the first connection parameter and the secondconnection parameter may be set identically, that is, set to the samevalue. When the first connection parameter and the second connectionparameter are identical to each other, the collision between packets maybe prevented by changing the timing at which each wireless powerreceiver exchanges packets with the wireless power transmitter. Theconnection parameter for the out-band communication may includeinformation on a connection interval with each master (the firstwireless power receiver and the second wireless power receiver).

FIG. 20 is a diagram showing the role structure of a wireless powertransmitter and a wireless power receiver according to another example,and FIG. 21 is a diagram illustrating a communication link betweendevices in the role structure according to FIG. 20.

Referring to FIG. 20, the wireless power transmitter (PTx) may operateas a scanner before being connected to the wireless power receiver, andmay operate as a master (GATT client) after being connected to thewireless power receiver. The wireless power receivers (PRxs) may operateas advertisers before being connected to the wireless power transmitter,and may operate as a scanner (GATT server) after being connected to thewireless power transmitter.

In the process of the wireless power transmitter charging a plurality ofwireless power receivers, a topology is created in which an out-bandcommunication module of one wireless power transmitter forms acommunication link with out-band communication modules of a plurality ofwireless power receivers. Considering the topology according to theBluetooth standard in which several slaves are connected to one masterdevice, the topology shown in FIG. 20 may be suitable for the wirelesspower transmission system.

Referring to FIG. 20, the wireless power transmitter operates as amaster. Accordingly, when one wireless power transmitter is connected totwo wireless power receivers, the wireless power transmitter can managetwo Bluetooth links. That is, as shown in FIG. 21, to prevent thecollision between packets exchanged between the wireless powertransmitter (master) and the first wireless power receiver (slave #1)and packets exchanged between the wireless power transmitter (master)and the second wireless power receiver (slave #2), the wireless powertransmitter may perform a scheduling operation in the time dimension.

According to this embodiment, the wireless power transmitter can adjusta first connection parameter for out-band communication with the firstwireless power receiver and a second connection parameter for out-bandcommunication with the second wireless power receiver. As an example,the first connection parameter and the second connection parameter maybe set identically, that is, set to the same value. The connectionparameter for the out-band communication may include information on aconnection interval with each master (the first wireless power receiverand the second wireless power receiver), it may be transmitted from thewireless power transmitter to each wireless power receiver. In FIG. 21,for example, a case of communicating with the wireless powercommunication device with a time difference of 7.5 ms and 37.5 ms,respectively, with the first wireless power receiver configuring sameconnection interval (45 ms in FIG. 21) to the second wireless powerreceiver is shown.

In terms of power consumption, it is highly likely that the wirelesspower transmitter is a powered device and the wireless power receiver isa battery-operated portable device. Therefore, it is suitable for thewireless power receiver to operate as an advertiser with low powerconsumption.

However, if the wireless power receiver is a low-power device such as asmartphone and Bluetooth is activated, the existing Bluetooth module ofa smartphone often operates as a scanner/master. Therefore, when theBluetooth module of the wireless power receiver in the smartphoneperforms the advertiser/slave role, a situation arises in which both theadvertiser/slave role and the scanner/master role must be performedwithin a single smartphone device. This may be inefficient in terms ofimplementation complexity or interference.

The wireless power transmitter in the embodiment according to FIGS. 17to 21 corresponds to the wireless power transmitter or the wirelesspower transmitter or the power transmitter disclosed in FIGS. 1 to 11.Accordingly, the operation of the wireless power transmitter in thisembodiment is implemented by one or a combination of two or more of eachcomponent of the wireless power transmitter in FIGS. 1 to 11. Forexample, the out-band (Bluetooth) communication module, the in-bandcommunication module, and the control unit according to FIGS. 17 to 21may be the communication/control circuit 120 or may be included in thecommunication/control circuit 120.

The wireless power receiver in the embodiment according to FIGS. 17 to21 corresponds to the wireless power reception device or wireless powerreceiver or power reception unit disclosed in FIGS. 1 to 11.Accordingly, the operation of the wireless power receiver in thisembodiment is implemented by one or a combination of two or more of therespective components of the wireless power receiver in FIGS. 1 to 11.For example, the out-band (Bluetooth) communication module, the in-bandcommunication module, and the control unit according to FIGS. 17 to 21may be the communication/control circuit 220 or may be included in thecommunication/control circuit 220.

Hereinafter, as an example, when the wireless power transmitter operatesas an advertiser and a slave, an efficient peripheral device searchmethod and a link management protocol or method are disclosed.

FIG. 22 is a flowchart illustrating a method in which a wireless powertransmitter and a wireless power receiver share a scan record andscheduling according to an embodiment.

Referring to FIG. 22, the first device is provided with a first out-bandcommunication module (OOB#1) separately from the second out-bandcommunication module (00B#2) included in the wireless power receiver.FIG. 22 shows that the BLE module is used as an out-band communicationmodule as an example, but an NFC module, a WIFI module, a Bluetoothcommunication module, etc. may be used as the out-band communicationmodule.

As an example, the first wireless power receiver provided in the firstdevice may use the first out-band communication module OOB#1 forwireless power transmission. That is, the first out-band communicationmodule OOB#1 may be used to perform a protocol related to wireless powertransmission. As another example, the first wireless power receiver isindependent of the first out-band communication module (OOB#1), that is,without (re)using the first out-band communication module (OOB#1) forwireless power transmission, it may further include a separate secondout-band communication module (OOB#2) dedicated to the wireless powertransmission protocol.

For example, when the wireless power transmitter operates as anadvertiser as shown in FIG. 22 and operates as a slave after BLEconnection, since the operation of the scanner consumes a lot of power,it is difficult for the second out-band communication module (OOB#2) ofthe first wireless power receiver to continue to operate as a scannerfor a long time. Therefore, the first wireless power receiver mayperform the step of appropriately setting the time when the secondout-band communication module OOB#2 starts the scanner operation (thatis, the time of the scanner event). To this end, when the in-bandcommunication module of the first wireless power receiver completesin-band communication with the wireless power transmitter, the secondout-band communication module (OOB#2) may be informed of the timing ofthe scanner event through the scanner event message (S2200). Here, thetime point at which the in-band communication is completed may be, forexample, a time point at which the identification and configuration stepof FIG. 5 or the configuration step of FIG. 11 is completed andtransition to the negotiation step.

When the second out-band communication module (OOB#2) operates as ascanner, it is possible for the second out-band communication moduleOOB#2 to receive information on the scan result from the first out-bandcommunication module OOB#1 (S2210). Therefore, if there is a scanhistory result obtained from a previous scan, the first out-bandcommunication module OOB#1 may transmit it to the second out-bandcommunication module OOB#2.

Referring back to FIG. 22, when the first out-band communication module(OOB#1) and the second out-band communication module (OOB#2) of thefirst wireless power receiver are connected to two different devices,both the first out-band communication module OOB#1 and the secondout-band communication module OOB#2 operate as masters. In this case,the first out-band communication module OOB#1 and the second out-bandcommunication module OOB#2 may share a connection parameter and achannel map used for their respective communication through a schedulingsharing message (S2220). Based on this, collisions that may occur whenthe first out-band communication module OOB#1 and the second out-bandcommunication module OOB#2 operate as masters can be avoided. Forexample, the first wireless power receiver performs a coexistencemechanism, so that the first out-band communication module OOB#1 and thesecond out-band communication module OOB#2 may perform an operation ofdistributing time to avoid simultaneous transmission.

After connection with the wireless power transmitter, the secondout-band communication module (OOB#2) of the first wireless powerreceiver and the second device (the second wireless power receiver) maytransmit and receive wireless charging-related information to and fromthe wireless power transmitter, respectively (S2230). At this time, whenthe second out-band communication module OOB#2 of the first wirelesspower receiver receives a retransmission request for the packettransmitted by the first wireless power receiver from the wireless powertransmitter (S2240), in order to avoid collision, scheduling informationmay be re-shared with the first out-band communication module OOB#1(S2250).

The wireless power transmitter in the embodiment according to FIG. 22corresponds to the wireless power transmission device or the wirelesspower transmitter or the power transmission unit disclosed in FIGS. 1 to11. Accordingly, the operation of the wireless power transmitter in thisembodiment is implemented by one or a combination of two or more of eachcomponent of the wireless power transmitter in FIGS. 1 to 11. Forexample, the out-band (Bluetooth) communication module, the in-bandcommunication module, and the control unit according to FIG. 22 may bethe communication/control circuit 120 or may be included in thecommunication/control circuit 120.

The wireless power receiver in the embodiment according to FIG. 22corresponds to the wireless power reception device or wireless powerreceiver or power reception unit disclosed in FIGS. 1 to 11.Accordingly, the operation of the wireless power receiver in thisembodiment is implemented by one or a combination of two or more of therespective components of the wireless power receiver in FIGS. 1 to 11.For example, the out-band (Bluetooth) communication module, the in-bandcommunication module, and the control unit according to FIG. 22 may bethe communication/control circuit 220 or may be included in thecommunication/control circuit 220 .

FIG. 23 is a flowchart illustrating a method of filtering an advertisingpacket according to an embodiment.

Referring to FIG. 23, the first wireless power receiver (or firstdevice) may include the first out-band communication module OOB#1regardless of the wireless power transmission system. As an example, thefirst wireless power receiver may use the first out-band communicationmodule OOB#1 for wireless power transmission. That is, the firstout-band communication module OOB#1 may be used to perform a protocolrelated to wireless power transmission. As another example, the firstwireless power receiver does not reuse the OOB#1 for wireless powertransmission regardless of the first out-band communication module(OOB#1), it may further include a separate second out-band communicationmodule (OOB#2) dedicated to the wireless power transmission protocol.

As shown in FIG. 23, when a plurality of out-band communication modules(OOB#1 and OOB#2) are independently implemented in the first wirelesspower receiver (or first device), the first out-band communicationmodule OOB#1 may operate as a scanner and the second out-bandcommunication module OOB#2 may operate as an advertiser. In this case,since the first out-band communication module OOB#1 operates as ascanner, it receives an advertising packet transmitted from the secondout-band communication module OOB#2 to the wireless power transmitter(S2300). Therefore, based on at least one of a device identifier and aservice identifier of the wireless power transmission system included ina packet received through out-band communication, the first out-bandcommunication module OOB#1 may filter the advertisement packettransmitted by the second out-band communication module OOB#2 (S230).

When the first out-band communication module (OOB#1) receives theadvertising packet from the second wireless power receiver (or thesecond device) (S2320), similarly, the packet may be filtered based onwhether the packet includes at least one of a device identifier and aservice identifier of the wireless power transmission system (S2330). Iffiltering is not performed in this way, the first out-band communicationmodule OOB#1 receives the advertising packet transmitted by the secondout-band module OOB#2, it can be determined that this is sent by anotherdevice. That is, a decision error may occur.

The wireless power transmitter in the embodiment according to FIG. 23corresponds to the wireless power transmission device or the wirelesspower transmitter or the power transmission unit disclosed in FIGS. 1 to11. Accordingly, the operation of the wireless power transmitter in thisembodiment is implemented by one or a combination of two or more of eachcomponent of the wireless power transmitter in FIGS. 1 to 11. Forexample, the out-band (Bluetooth) communication module, the in-bandcommunication module, and the control unit according to FIG. 23 may bethe communication/control circuit 120 or may be included in thecommunication/control circuit 120 .

The wireless power receiver in the embodiment according to FIG. 23corresponds to the wireless power receiver or wireless power receiver orpower receiver disclosed in FIGS. 1 to 11. Accordingly, the operation ofthe wireless power receiver in this embodiment is implemented by one ora combination of two or more of the respective components of thewireless power receiver in FIGS. 1 to 11. For example, the out-band(Bluetooth) communication module, the in-band communication module, andthe control unit according to FIG. 23 may be the communication/controlcircuit 220 or may be included in the communication/control circuit 220.

FIG. 24 is a flowchart illustrating a communication method when thewireless power transmitter operates as a master and a scanner accordingto an embodiment.

As shown in FIG. 24, when the wireless power transmitter operates as ascanner and operates as a master after BLE connection, the out-bandcommunication module (OOB#1) of the first wireless power receiver (firstdevice) should perform four roles. That is, it must operate in fourmodes. Here, in the implementation, the operating time for each role isdefined as a mode interval.

The wireless power receiver operates in advertiser mode and scanner modein a state not connected to the wireless power transmitter, and operatesin slave mode and master mode while connected to the wireless powertransmitter. The first wireless power receiver and the second wirelesspower receiver each transmit an advertising packet to the wireless powertransmitter in the advertiser mode (S2400). Each wireless power receiveroperates in slave mode when connected to a wireless power transmitter,each wireless power receiver may transmit mode interval informationoperated by itself to the wireless power transmitter (S2410). The modeinterval information may be used by the wireless power transmitter toschedule communication between the first wireless power receiver and thesecond wireless power receiver. The wireless power transmitter transmitsand receives wireless charging-related information with the firstwireless power transmitter at a time when the first wireless powertransmitter operates in the slave mode based on the schedulinginformation set based on the mode interval information (S2420), thewireless power transmitter may transmit/receive wirelesscharging-related information to and from the second wireless powertransmitter while the second wireless power transmitter operates in theslave mode (S2430). For example, when the time interval during which thefirst wireless power receiver operates as a slave is 50 ms, the wirelesspower transmitter sets the connection interval with the out-bandcommunication module of the first wireless power receiver to 50 ms ormore, other time resources may be allocated to other devices such as thesecond wireless power receiver.

The wireless power transmitter in the embodiment according to FIG. 24corresponds to the wireless power transmission device or the wirelesspower transmitter or the power transmission unit disclosed in FIGS. 1 to11. Accordingly, the operation of the wireless power transmitter in thisembodiment is implemented by one or a combination of two or more of therespective components of the wireless power transmitter in FIGS. 1 to11. For example, the out-band (Bluetooth) communication module, thein-band communication module, and the control unit according to FIG. 24may be the communication/control circuit 120 or may be included in thecommunication/control circuit 120.

The wireless power receiver in the embodiment according to FIG. 24corresponds to the wireless power reception device or wireless powerreceiver or power reception unit disclosed in FIGS. 1 to 11.Accordingly, the operation of the wireless power receiver in thisembodiment is implemented by one or a combination of two or more of therespective components of the wireless power receiver in FIGS. 1 to 11.For example, the out-band (Bluetooth) communication module, the in-bandcommunication module, and the control unit according to FIG. 24 may bethe communication/control circuit 220 or may be included in thecommunication/control circuit 220 .

Since all components or steps are not essential for the wireless powertransmission method and apparatus or the receiving apparatus and methodaccording to the present embodiment described above, the wireless powertransmitter and method, or the receiver and method may be performed byincluding some or all of the above-described components or steps. Inaddition, the above-described wireless power transmitter and method, orthe embodiment of the receiver and method may be performed incombination with each other. In addition, each of the above-describedcomponents or steps is not necessarily performed in the order described,and it is also possible that the steps described later are performedbefore the steps described earlier.

The above description is merely illustrative of the technical idea ofthe present disclosure, those of ordinary skill in the art to which thepresent disclosure pertains will be able to make various modificationsand variations without departing from the essential characteristics ofthe present disclosure. Accordingly, the embodiments of the presentdisclosure described above may be implemented separately or incombination with each other.

Accordingly, the embodiments disclosed in the present disclosure are notintended to limit the technical spirit of the present disclosure, but toexplain, and the scope of the technical spirit of the present disclosureis not limited by these embodiments. The protection scope of the presentdisclosure should be interpreted by the following claims, and alltechnical ideas within the scope equivalent thereto should be construedas being included in the scope of the present disclosure.

What is claimed is:
 1. A wireless power receiver comprising: a powerpickup circuit configured to: receive a wireless power from a wirelesspower transmitter by a magnetic coupling with the wireless powertransmitter having a primary coil at an operating frequency, and convertan AC signal generated by the wireless power into a DC signal; acommunication circuit configured to: perform an in-band communicationwith the wireless power transmitter using the operating frequency, andperform an out-band communication with the wireless power transmitter orother device using a frequency other than the operating frequency; and acontrol circuit configured to control an overall operation of thewireless power receiver, wherein a first connection parameter for anout-band communication between the wireless power transmitter and thewireless power receiver is configured a same as a second connectionparameter for an out-band communication between the wireless powertransmitter and other wireless power receiver.
 2. The wireless powerreceiver of claim 1, wherein the communication circuit is configured toreceive information for the first connection parameter through theout-band communication from the wireless power transmitter.
 3. Thewireless power receiver of claim 1, wherein the communication circuit isconfigured to transmit information for an interval of switching from afirst mode to a second mode to the wireless power transmitter using anout-band communication.
 4. The wireless power receiver of claim 3,wherein the first mode and the second mode include a mode in which thewireless power receiver or the communication circuit operates as amaster and a mode in which the wireless power receiver or thecommunication circuit operates as a slave.
 5. The wireless powerreceiver of claim 1, wherein the communication circuit comprises: afirst out-band communication module configured to perform the out-bandcommunication with the other device using the frequency other than theoperating frequency; and a second out-band communication moduleconfigured to perform the out-band communication with the wireless powertransmitter using the frequency other than the operating frequency. 6.The wireless power receiver of claim 5, wherein the first out-bandcommunication module and the second out-band communication module shareat least one of information about a scan record and schedulinginformation about an out-band communication with each other.
 7. Thewireless power receiver of claim 6, wherein the second out-bandcommunication module shares the scheduling information with the firstout-band communication module when a retransmission request for a packettransmitted by the wireless power receiver is received from the wirelesspower transmitter.
 8. The wireless power receiver of claim 6, whereinthe scheduling information includes a connection interval and a channelmap for an out-band communication.
 9. The wireless power receiver ofclaim 1, wherein the communication circuit filters a packet based on atleast one of a device identifier and a service identifier included inthe packet received through the out-band communication.
 10. A wirelesspower transmitter, which supports a heterogeneous communication,comprising: a power conversion circuit, which has a plurality of primarycoil, configured to transmit a wireless power to a wireless powerreceiver using a primary coil that forms a magnetic coupling with thewireless power receiver at an operating frequency; and acommunication/control circuit configured to: perform an in-bandcommunication with the wireless power receiver using the operatingfrequency, and perform an out-band communication with the wireless powerreceiver using a frequency other than the operating frequency, whereinthe communication/control circuit configured to set a first connectionparameter for an out-band communication with a first wireless powerreceiver as same as a second connection parameter for an out-bandcommunication with a second wireless power receiver.
 11. The wirelesspower transmitter of claim 10, wherein the communication/control circuitis configured to transmit information for the first connection parameterto the first wireless power receiver through the out-band communication.12. The wireless power transmitter of claim 10, wherein thecommunication/control circuit is configured to: receive, from thewireless power receiver, information for an interval at which thewireless power receiver is switched from a first mode to a second mode,and schedule the out-band communication with the wireless power receiverbased on the information for the interval.
 13. The wireless powertransmitter of claim 12, wherein the first mode and the second modeinclude a mode in which the wireless power receiver operates as a masterand a mode in which the wireless power receiver operates as a slave. 14.The wireless power transmitter of claim 10, wherein thecommunication/control circuit filters a packet based on at least one ofa device identifier and a service identifier included in the packetreceived from the wireless power receiver.